REMOTE DAS POD Model RA1216 USER MANUAL
Contents
1. 3 6 set sample R te 2 Reale I BE De 3 6 Read Sampl Rate 22 24 u ea en pe vee ee in ln ee 3 7 Configure Bits as Input or 3 7 Read Digital lnp ts u De Ra a a 3 8 Digital OUTPUTS u nu ia en Gln acetals Gok 3 8 Read Firmware Revision Number 3 9 Resend Last RESPONSE areae Bat wa mer er eet ae haba PA ear de eb 3 9 Configure Baud Rate ii ca ede ik etd ie ee Bad ne Hee 3 10 Configure Pod Address 3 11 Address Select 24 gd eae eee aed ad nei ame eae Lewd weed etd es 3 11 Entera New Program as 240 2 2 Py re Pe Dealer Gib eee elie Sete 3 11 SPECIFICATIONS tara Mend oa en GL Pee eae ae en 4 1 SERIAL COMMUNICATIONS INTERFACE 0 00 eee 4 1 ANALOG INPUTS baer bee a wa eh ee Ee he deo Ee 4 1 DIGITAL VO 12 Mer ene bd elven Bo hy ae Aa hens ed Pe Be ag nwa 4 2 POWER REQUIRED ii 22 42 52 bie a ean ea lie Shed We te a oe De 4 2 WARRANTY Ss Rn Satis ie inten oie lee Bian tele Sue athe Boa reinste 5 1 APPLICATION CONSIDERATIONS ccc eee A 1 REMOTE DAS POD MODEL RA1216 USER MANUAL Files contained on the 3 5 inch diskette are as follows SETUP amp CALIBRATION PROGRAM A menu dr2. 1 8 FUNCTIONAL DESCRIPTION 4 22 20 Pah Era Me aad Hebel pad pte laa Cas 2 1 ANALOG INPUTS Seat dias ae ets Pe Dan Obes wel Gee eve a Wier ea Phage ale 2 2 PROGRAMMABLE OFFSET 2 ee rege ie Aah Sokal eels 2 2 ANALOG OUTPUT Sys Bau Pav ah re ae ee cals Rae en ee 2 2 DIGITAL TVO a ee apa Lata bt A PAM AAG Fee ee Ae ew a 2 2 WATCHDOG TIMER Pe ee Pecos Dr vind Wad tte eee hd earn 2 3 BLOCK DIAGRAM bee a oa ae ee 2 3 SOFTWARE fcc Bs eee ee eee ea ele et ne ee 3 1 GENERAL 7 222320 tet athe Wales ee eee guage Ws Obs Oe ee a ee 3 1 COMMAND STRUCTURE cesoie ayna e ae a Tai a 3 1 Addressed Mode 2 ae mu an woh Ba Gee aa ee le et pe ee eh eee a 3 1 Concepts Onboard Digital O 3 1 Concepts The Point List Buffer css sea 0 ee 3 2 RA1216 COMMAND LIST en rren gnen ou pa ee 3 3 COMMAND FUNCTIONS 1 2 eee 3 5 Configure Point LISt iq pue mtaa wart eee a ne ae ee wee eG OF 3 5 Read Point LG Gok ae eat eee mean ale Bet Eat 3 5 Write PointListto EEPROM 0 0000 eee 3 5 Restore Point List un wk oo oe eee RR IR rer ee 3 5 Write Calibration Parameters 3 5 Return Calibration 5
3. Each input can be programmed with an offset of 2 5Vgenerated by a digital to analog converter This allows easy scaling and shifting of an input signal to take advantage of the pod s full input ranges ANALOG OUTPUTS Three 12 bit digital to analog converters provide simultaneous voltage and current outputs Voltage outputs are independently programmable in two ranges 0 5V and 0 10V Simultaneously each D Acan provide 4 20 mA outputs These current outputs are derived for user supplied compliance voltages from 5 5V to 30V DIGITAL I O Seven bits of digital I O are provided These can be software configured on a bit by bit basis as either inputs or outputs Digital inputs are sensed at TTL levels There is one interrupt input Each digital output provides compliance with user supplied voltages up to 50 VDC and the maximum sink current per output bit is 350 mA The maximum total sink current is limited to 650 mA on all seven bits All bits have a factory installed 10K pull up resistor to 5Volts REMOTE DAS POD MODEL RA1216 USER MANUAL WATCHDOG TIMER The built in watchdog timer resets the pod if the microcontroller hangs up or the power supply voltage drops below 7 5 VDC The microcontroller can also be reset by an external manual pushbutton input available at the interface connector POWER SUPPLIES RA1216 requires two power sources to maintain opto isolation A small amount of 7 5V to 24V power 50 mA is required by th
4. PLnn DEFAULT Sets point nn to default configuration 5V span no offset S E CR the current user calibration The factory cal is stored permanently in EEPROM during the initial calibration REMOTE DAS POD MODEL RA1216 USER MANUAL Mxx Set bits as Inputs or Outputs Each bit of xx controls a single bit of CR the DIO port One s set the corresponding port as output zeroes set the port as input Writing to a port marked as input will fail Power on default is ALL INPUTS Mx Turns bit x to input CR Sets output bit x 0 6 to ONE CR This command reads the seven digital inputs xx CR In Single bit read from bit 0 6 O CR or 1 CR AXXXXXX Acquires a single channel and returns the data immediately via the XXXX CR serial port bypassing the point list This command takes as its sole argument the same 3 byte parameter passed to the PL series of commands The channel specified in the parameter is acquired using the range polarity and MUX gain specified The data is returned immediately unlike the AC command ACnn nny Xxxx Acquires point list entries nn through nn with a total of xxxx CR Ann nn2 XXxX conversions performed xxxx must be equal to or less than 2710hex which is 10000 decimal allnumbers must be presented to the Pod in hex 10000 data samples is the maximum internal storage capacity of the standard Pod Optional firmware can increase this capacity Contact th
5. 9 LSB maximum Monotonicity 7 bit Output Range 0 5V 0 10V Current Output 4 20 mA User supplied excitation of 5 5V 30V Output Drive 5 mA Output Resistance 0 5 Settling Time 15 usec to 72 LSB 4 1 REMOTE DAS POD MODEL RA1216 USER MANUAL DIGITAL I O Seven bits configured as input or output Digital Inputs Logic High 2 0V to 50V at 20 max 5mA max at 50V in Protected to 200 VDC Logic Low 30V to 0 8V at 0 4 mA max Protected to 140 VDC Digital Outputs Logic Low Sink Current 350 mA maximum See note below Inductive kick suppression diode included in the each circuit NOTE Maximum allowable current per output bit is 350 mA When all seven bits are used there is a maximum total current of 650 mA High Level Output Voltage Open Collector compliance with up to 50VDC user supplied voltage If no user supplied voltage exists outputs pulled up to 5VDC via 10 resistors INTERRUPT INPUT For use with development kit Input Low 0 3V to 0 8V Input Low Current at 0 45V 55 pA Input High 2 0V to 5 0V POWER REQUIRED Power can be applied from the computer s 12VDC power supply for the opto isolated section via the serial communication cable and from a local power supply for the rest of the unit If you do not wish to use power from the computer a central power supply may be used for the opto isolated section Local Power 12 to 16 VDC 500 mA See box that follows Opto Isol
6. Bit 3 6 DIO2 Digital VO Bit 2 7 DIOS Digital I O Bit 5 8 DIO4 Digital I O Bit 4 9 APPLV Ext Dig Out Power 10 DIO6 Digital I O Bit 6 11 PBRST Ext Reset for uCtrlr 12 1SOV Isol Pwr 13 ISOGND Isol Pwr Ground 14 PTO Input to Counter 0 15 Vcc10 10V Pwr Ext Sens 16 PINT1 Interrupt 1 17 PWR Local Pwr 18 GND Digital Pwr Ground 19 AOGND Analog Output Ground 20 GND Local Pwr Ground 21 AOUTO Analog Output 0 Volt 22 IOUTO Analog Output 0 Current 23 AOUT1 Analog Output 1 Volt 24 IOUT1 Analog Output 1 Current 25 AOUT2 Analog Output 2 Volt 26 IOUT2 Analog Output 2 Current 27 AGND Analog Input Ground 28 AGND Analog Output Ground 29 CHOO Analog Input Chl O 30 CHO4 Analog Input Chi 4 31 CHOO Diff Analog Input Chl O 32 CHOA Diff Analog Input Chl 4 Or S E Analog Input 8 Or S E Analog Input Chl 12 33 AGND Analog Input Ground 34 AGND Analog Input Ground 35 CHO1 Analog Input Chl 1 36 CHO5 Analog Input Chl 5 37 CHO1 Diff Analog Input Chl 1 38 5 Diff Analog Input Chl 5 Or S E Analog Input Chl 9 Or S E Analog Input Chl 13 39 AGND Analog Input Ground 40 AGND Analog Input Ground 41 CHO2 Analog Input Chl 2 42 CHO6 Analog Input Chl 6 43 CH02 Diff Analog Input Chi 2 44 CHO6 Diff Analog Input Chl 6 Or S E Analog Input Chl 10 Or S E Analog Input Chl 14
7. Offset DAC setting some setup is necessary to improve usability The setup consists of telling the Pod the input range and Diff SE for each channel and the order in which to acquire the channels This is done using the Point List PL series of commands The Point List is a list of the channels to be acquired along with all of the configuration information for each channel All of the commands to set PL entries take a point number or the keyphrase ALL and a 3 byte 6 hex digit value describing the configuration for that point or the keyphrase DEFAULT ALL numbers passed to and from the Pod are in hexadecimal 3 2 REMOTE DAS POD MODEL RA1216 USER MANUAL RA1216 COMMAND LIST Command Returns Description PROGRAM Use with caution Loads new firmware into the Pod s EEPROM Use ESC ASCII 27 to abort Vertical Bar Same as PROGRAMS except used only after a reset to gain access to Pod BAUD nnn Sets Baud rate Sets the Pod address to xx Sets the Sample Rate of the A D Valid ranges 00A2 through FFFF Value passed is the desired divisor of the rate clock 00A2 is 6666Hz or 150us sample 039A is 1000Hz or 1ms sample 11 059 200Hz 12 timebase Hz sample rate Returns the Clock Divisor from EEPROM on the Pod as above xxxx CR 5 Address Select Command Selects the Pod at address xx for CR communication H Hello command H followed by anything returns Pod n
8. Same as PROGRAM except it is used only after a reset has occurred Allows access to Pod to download new firmware ERROR CODES The following error codes can be returned from the Pod 1 Invalid channel number too large or not a number All channel numbers must be between 00 and OF in hex 3 Improper Syntax Not enough parameters is the usual culprit 4 Channel number is invalid for this task For example if you try to output to a bit that is set as an input bit that will cause this error 9 Parity error This occurs when some part of the received data contains a parity or framing error Additionally several full text error codes are returned All begin with Error and are useful when using a terminal to program the Pod Error Unrecognized Command command received CR This occurs if the command is not recognized Error Command not fully recognized Command received CR This occurs if the first letter of the command is valid but the remaining letters are not Error Address command must be CR terminated CR This occurs if the address command xx CR has extra characters between the Pod number and the CR 3 12 REMOTE DAS POD MODEL RA1216 USER MANUAL SPECIFICATIONS SERIAL COMMUNICATIONS INTERFACE Serial Port Opto isolated Matlabs type LTC485 Transmitter Receiver Compatible with RS 485 specification Up to 32 drivers and receivers allowed on the line I O bus programmable from 00 to FF he
9. X XX CR Example Read the RA1216 version number SEND V RECEIVE 1 00 CR NOTE The H command returns the version number along with other information See Hello Message on next page Resend Last Response n Resend last response This command will cause the Pod to return the same thing it just sent This command works for all responses less than 255 characters in length Normally this command is used if the host detected a parity or other line fault while receiving data and needs the data to be sent a second time The command may be repeated Example Assuming the last command was I ask Pod to resend last response SEND n RECEIVE FFFFFF CR whatever the data was Hello Message H Hello message Any string of characters starting with H will be interpreted as this command H CR 3 9 REMOTE DAS POD MODEL RA1216 USER MANUAL alone is also acceptable The return from this command takes the form without the quotes Pod aa RA1216 Rev rr Firmware Ver x xx ACCES I O Products Inc aa is the Pod address rr is the hardware revision such as 1 x xx is the software revision such as 1 00 Example Read the greeting message SEND Hello RECEIVE Pod 00 RA1216 Rev B1 Firmware Ver 1 00 ACCES I O Products Inc CR Configure Baud Rate When initially shipped the baud rate is set at 9600 BAUD nnn Program the Pod with a new baud rate This command set
10. and AOGND These are the terminals for RS 485 serial communications Analog voltage input terminals Analog voltage output terminals IOUTO 2 4 to 20mA current output terminals 0100 6 Digital input output terminals APPLV This terminal is for the application power or the user provided voltage level to which digital outputs are connected through the loads Open collector Darlington amplifiers are used at the outputs Inductive suppression diodes are included in the APPLV circuit If inductive loads are being driven this must be connected The application power level APPLV can be as high as 50 VDC REMOTE DAS POD MODEL RA1216 USER MANUAL FUNCTIONAL DESCRIPTION FEATURES Remote Intelligent Analog and Digital I O Unit with Opto Isolated RS 485 Serial Interface to Host Computer Eight Differential or Sixteen Single ended Analog Inputs Programmable Gain and Offset on a Channel by Channel Basis 12 Bit Resolution A D Converter Optional Signal Conditioning for Use with Thermocouples RTDs 4 20 mA Current Inputs and Resistors for Strain Gage Bridge Completion Three 12 Bit D A Converters with Both Voltage and Current Outputs Seven Bits of Digital I O Configured on a Bit by Bit Basis as Either Inputs or High Current Outputs Onboard 16 Bit 8031 Compatible Microcontroller with 32K x 8 bits and 32K x 8 bits EEPROM All Programming and Calibration in Software No Switches to Set J
11. is configured to be in addressed mode it is necessary to issue an address command to the Pod at the new address before it will respond The Pod returns a message containing the Pod number as confirmation Examples Set the Pod address to 01 SEND A 01 RECEIVE Pod 01 CR Set the Pod address to F3 SEND A F3 RECEIVE Pod F3 CR Take the Pod out of addressed mode SEND A 00 RECEIVE Pod 00 CR Address Select Ixx Selects the Pod addressed xx NOTE When using more than one Pod in a system each Pod is configured with a unique address This command must be issued prior to any other commands to that particular Pod This command needs to be issued only once prior to executing any other commands Once the address select command has been issued that Pod will respond to all other commands until a new address select command is issued Enter aNew Program PROGRAMS This command initiates transfer of a new program to the RA1216 This command should be used carefully If you accidentally issue a PROGRAM command ESC ASCII 27 will restart the Pod as if power had been reset This feature is designed to allow ACCES to provide field upgrades to the RA1216 firmware and for advanced users the opportunity to customize the firmware in the Pod Documentation on using this command is provided with the upgrade diskette or is available separately for a small fee 3 11 REMOTE DAS POD MODEL RA1216 USER MANUAL Vertical Bar
12. protocol must be used when there is more than one REMOTE ACCES pod The difference is that an address command is sent to enable the specific pod The address command is only sent once during communication between the specific pod and the host computer It enables communication with that specific pod and disables all other REMOTE ACCES devices from communicating on the network COMMAND STRUCTURE All communication must be 7 data bits even parity 1 stop bit All numbers sent to and received from the pod are in hexadecimal form The factory default baud rate is 9600 Baud The pod is considered to be in addressed mode any time its pod address is not 00 The factory default pod address is 00 non addressed mode Addressed Mode The address select command must be issued before any other command to the addressed pod The address command is as follows Ixx CR where xx is the pod address from 01 to FF hex and CR is Carriage Return ASCII character 13 The pod responds with CR Once the address select command has been issued all further commands other than a new address select will be executed by the selected pod The addressed mode is required when using more than one pod When there s only one pod connected no address select command is needed Pod commands are listed in the following table Terminology used is as follows The single lower case letter x designates any valid hex digit 0 The symbol desig
13. the ACCES designated Service Center and will be returned to the customer s user s site freight prepaid and invoiced COVERAGE First Three Years Returned unit part will be repaired and or replaced at ACCES option with no charge for labor or parts not excluded by warranty Warranty commences with equipment shipment Following Years Throughout your equipment s lifetime ACCES stands ready to provide on site or in plant service at reasonable rates similar to those of other manufacturers in the industry EQUIPMENT NOT MANUFACTURED BY ACCES Equipment provided but not manufactured by ACCES is warranted and will be repaired according to the terms and conditions of the respective equipment manufacturer s warranty GENERAL Under this Warranty liability of ACCES is limited to replacing repairing or issuing credit at ACCES discretion for any products which are proved to be defective during the warranty period In no case is ACCES liable for consequential or special damage arising from use or misuse of our product The customer is responsible for all charges caused by modifications or additions to ACCES equipment not approved in writing by ACCES or if in ACCES opinion the equipment has been subjected to abnormal use Abnormal use for purposes of this warranty is defined as any use to which the equipment is exposed other than that use specified or intended as evidenced by purchase or sales representation Other than the above no other warrant
14. 45 AGND Analog Input Ground 46 AGND Analog Input Ground 47 Analog Input Chl 48 CHO7 Analog Input Chl 7 49 CHOS Diff Analog Input Chi 3 50 CHO7 Diff Analog Input Chl 7 Or S E Analog Input Chl 11 Or S E Analog Input Chi 15 REMOTE DAS POD MODEL RA1216 USER MANUAL Pin Description PWR PWR GND ISOV and ISOGND These terminals are used to apply power to the pod from a local power supply The voltage can be anywhere in the range of 12 VDC to 16 VDC Higher voltage can be used 24 VDC for example if an external Zener diode is used to reduce the voltage applied to the RA1216 See the Specification section of this manual to determine the Zener diode power rating required This is the power connection for the isolator section that may be supplied from the computer s 12VDC supply via a pair of wires on the RS 485 network or from a central power supply This power is independent of local power The voltage level can be from 7 5 VDC to 35 VDC An on board voltage regulator regulates the power to 5 VDC The RA1216 requires only 5mA of current when idling and 33mA current when data is being transmitted so any loading effects on the computer power will be minimal Note If separate power is not available ISOV and ISOGND must be jumpered to the local power terminals which defeats the optical isolation RS485 and RS485 CHO 7 and AGND AOUTO 2
15. A balanced line driver will produce a differential voltage from 2 to 6 volts across its output terminals A balanced line driver can also have an input enable signal that connects the driver to its output terminals If the enable signal is OFF the driver is disconnected from the transmission line This disconnected or disabled condition is usually referred to as the tristate condition and represents a high impedance RS 485 drivers must have this control capability RS 422 drivers may have this control but it is not always required Abalanced differential line receiver senses the voltage state of the transmission line across 1 REMOTE DAS POD MODEL RA1216 USER MANUAL the two signal input lines If the differential input voltage is greater than 200 mV the receiver will provide a specific logic state on its output If the differential voltage input is less than 200 mV the receiver will provide the opposite logic state on its output A maximum operating voltage range is from 6V to 6V allows for voltage attenuation that can occur on long transmission cables A maximum common mode voltage rating of 7V provides good noise immunity from voltages induced on the twisted pair lines The signal ground line connection is necessary in order to keep the common mode voltage within that range The circuit may operate without the ground connection but may not be reliable RS 422 SPECIFICATION SUMMARY Parameter Conditions Driver O
16. A1216 USER MANUAL ANALOG INPUTS RA1216 uses a 12 bit successive approximation analog to digital converter A D capable of up to 50 000 conversions per second A D conversions may be initiated either by software command or by an external input The RA1216 accepts up to sixteen single ended analog inputs or eight differential Solid state multiplexers are used and to prevent crosstalk and increase stability between channels the input of the multiplexer is shorted to ground before each channel selection for a time period sufficient to discharge the multiplexer s output capacitance The RA1216 can be configured to accept inputs from a variety of sensor types The standard configuration is for voltage inputs For thermocouple inputs an on board temperature sensor is used to provide input for cold junction compensation and break detect resistors are available specify RA1216T C The pod can accept inputs from three wire RTDs or 4 20 mA transmitter circuits RA1216R or RA1216l respectively It can also be configured to provide bridge completion in quarter bridge Strain Gage applications RA1216B C Eight analog voltage spans and a 4 20 mA current input range are available All inputs are internally protected up to 200 VDC The Programmable Gain Amplifier consists of a programmable gain instrumentation amplifier and a programmable gain operational amplifier This increases the signal conditioning flexibility of the pod PROGRAMMABLE OFFSET
17. ame See Desc revision and copyright message N Resend last message Causes the Pod to re transmit last See Desc message Should be used upon parity error for example V Reads the version number from the firmware PLnn xxxxxx Set Point List Entry for point number nn to xxxxxx See Concepts CR The Point for more information on the point configuration setup required to use the PL commands PLnn Reads the Point List entry for point number nn PLALL Reads the Point Configuration for all points 0 40 hex Data is See Desc returned as XXXXXX XXXXXX XXXXXX CR with a total of 64 entries PLALL DEFAULT Sets all points to default configuration 5V span entries O F A D CR channel 0 F S E all other entries AD channel 0 BACKUP PL Stores the point list into the onboard EEPROM for power off safekeeping The point list is restored automatically every time the Pod is reset or using the PLALL BACKUP command CR PLALL BACKUP Restores the EEPROM point list into the current point list This CR command is executed automatically upon Pod reset CALNn xxxx XXXX Writes offset and scale calibration constants n used for CR Y MX B calibration Used by setup calibration procedures CALn Returns stored calibration constant n See sample program on xxxx xxxx disk for example usage CR CAL BACKUP Use this command to restore the factory calibration overwriting
18. amples per second SEND S 0385 RECEIVE CR 2 REMOTE DAS POD MODEL RA1216 USER MANUAL NOTE The sample rate configured is stored in EEPROM on the Pod and will be used as the default power on sample rate The factory default sample rate 100Hz can be restored by sending S0000 to the Pod Read Sample Rate 5 Returns the clock Divisor EEPROM on the Pod Special Acquisition Commands Acquires Point List entries nn through nn with a total of xxxx conversions performed xxxx must be equal to or less than 2710hex which is 10000 decimal all numbers must be presented to the Pod in hex 10000 data samples is the maximum internal storage capacity of the standard Pod Optional firmware can increase this capacity Contact the factory for further information Please note that this function does not return any data Data is stored in the internal SRAM storage for later retrieval using the R command R This command reads the last buffer of data acquired using the AC command The data is returned in CCXXXX CCXXXX CCXXXX CR format where CC is the point number that was acquired and XXXX is the analog conversion data The total number of return values is identical to the XXXX parameter passed to the most recently issued AC command AXXXXXX Acquires a single channel and returns the data immediately via the serial port bypassing the point list This command takes as its sole argu
19. ated Section 7 5 to 24 VDC 50 mA Note Due to the small amount of current required voltage drop in long cables is not significant If the local power supply has an output voltage greater than 16VDC you can install a Zener diode in series with the supply voltage The voltage rating of the Zener diode V should be equal to V 16 where V is the power supply voltage The power rating of the Zener diode should be gt x 0 35 watts Thus for example a 24VDC power supply would require using an 8 2V Zener diode with a power rating of 8 2 x 0 35 3 watt REMOTE DAS POD MODEL RA1216 USER MANUAL WARRANTY Prior to shipment ACCES products are thoroughly inspected and tested to applicable specifications However should equipment failure occur ACCES assures its customers that prompt service and support will be available All equipment originally manufactured by ACCES which is found to be defective will be repaired or replaced subject to the following considerations TERMS AND CONDITIONS If a unit is suspected of failure contact ACCES Customer Service department Be prepared to give the model number serial number and a description of the failure symptom s We may suggest some simple tests to confirm the failure We will assign a Return Material Authorization RMA number which must appear on the outer label of the return package All units components should be properly packed for handling and returned freight prepaid to
20. both ends of the line but not at drop points in the middle of the line TERMINATION RESISTORS AT BOTH ENDS ONLY TX ENABLE TX ENABLE RX ENABLE RX ENABLE TX ENABLE TX ENABLE RX ENABLE 9 RX ENABLE Typical RS 485 Two Wire Multidrop Network A 3
21. e factory for further inform ation Please note that this function does not return any data Data is stored in internal SRAM storage for later retrieval using the R command The A command works very similarly to the AC command All parameters are the same However the A command runs in the foreground occupying all of the attention of the Pod s microcontroller This yields higher throughput but sacrifices flexibility The Pod acquires data at its fastest possible rate Data is stored in internal SRAM storage for later retrieval using the R command CR This command reads the last buffer of data acquired using the AC see desc or A command The data is returned in CCXXXX CCXXXX CC XXXX CR format where CC is the pointnumber that was acquired and XXXX is the analog conversion data The total number of return values is identical to the XXXX parameter passed to the most recently issued AC command Set analog output n to xxxx with 0 5V range if m is 0 or 0 10V range if m is 1 xxx is hexadecimal counts 000 is OV FFF is full scale 5V or 10V 800 is half scale 2 5V or 5V etc Similar to the An command but sets all three analog outputs to the same value NOTE Pod reset occurs upon power up programming process or watchdog time out REMOTE DAS POD MODEL RA1216 USER MANUAL COMMAND FUNCTIONS The following paragraphs give details of the command functions describe what the commands cause and give
22. e opto isolated RS485 circuitry this can be supplied by the host computer through the cable carrying the RS485 serial data Alternatively you can use an external power supply The remainder of the RA1216 circuitry is powered by an external power supply of 12V to 16V 500mA BLOCK DIAGRAM XTAL WATCHDOG 8 Diff 16 S E OSC CIRCUIT INPUT 12 BIT A D ANALOG MUX CONVERTER INPUTS OFFSET CONTROL 12 BIT D A DECODE CONVERTER LOGIC TXD DS80C310 TxEen MICRO ISOLATORS CONTROLLER RS485 RS485 PORT XCVR 5V ISO PWR VOLTAGE REGULATOR ISO GND OFFSET DAC ADDRESS N TYPE VOLTAGE OUT DACO CURRENT OUT 4 20mA 12 BIT D A 9 CONVERTER VOLTAGE OUT DAC 1 CURRENT OUT 4 20mA 12 BIT D A 9 CONVERTER VOLTAGE OUT J DAC 2 CURRENT OUT 4 20mA 12 BIT D A CONVERTER SRAM EEPROM 32 32K DI O 0 7 THROUGH BITS DI O 6 DO VOLTAGE POWER REGULATORS 2 3 REMOTE DAS POD MODEL RA1216 USER MANUAL SOFTWARE GENERAL The RA1216 comes with ASCll based software provided on CD or diskette ASCII programming permits you to write applications in any high level language that supports ASCII text string functions This allows REMOTE ACCES series modules to be used with virtually any computer that has an RS 485 port The communication protocol has two forms addressed and non addressed Non addressed protocol is used when there is only one REMOTE ACCES pod Addressed
23. el captive screws The mounting holes and cover attaching screws are outside the sealed area to prevent ingress of moisture and dust Four threaded bosses inside the enclosure provide for mounting the printed circuit board assemblies Micro controller board setup JP2 JP3 and JP4 ISL position TXD RXD and TXEN are opto isolated from the host computer In the NSL position the opto isolators are by passed This position allows for a single power supply and higher baud rates Personality board setup OFFSET DAC jumper OFST position analog inputs are offset by a value set by the user GND position the OFFSET DAC has no effect on the analog input readings REMOTE DAS POD MODEL RA1216 USER MANUAL INPUT OUTPUT CONNECTIONS Electrical connections to the RA1216 are through watertight glands that seal the wires terminated inside to a Euro style screw terminal block that plugs into a 50 pin connector To ensure that there is minimum susceptibility to EMI and minimum radiation it is important that there be a positive chassis ground Also proper EMI cabling techniques cable connected to chassis ground twisted pair wiring and in extreme cases ferrite level of EMI protection may be needed for input output wiring 50 Pin Connector Connector pin assignments for the 50 pin connector are listed below Pin Pin 1 RS485 Comm Line 2 RS485 Comm Line 3 DIO1 Digital I O Bit 1 4 DIOO Digital I O Bit 0 5 DIO3 Digital I O
24. examples Please note that all commands have an acknowledgment response You must wait for a response from a command before sending another command Configure Point List PLnn xxxxxx Sets point list entry for point number nn to xxxxxx PLnn DEFAULT Sets point nn to default configuration PLALL DEFAULT Sets all points to default configuration NOTE Default configuration is 0 5V Single Ended Read Point List PLnn Reads the point configuration for point number nn PLALL Reads the point configuration for all points 0 127 NOTE Data is returned as with total of 64 entries Write Point List to EEPROM BACKUP PL Stores the point list configuration in the onboard EEPROM for power off safekeeping NOTE The point list configuration is automatically restored every time the Pod is reset or when PLALL BACKUP command is issued Restore Point List PLALL BACKUP Restores point list configuration in EEPROM to the current point list NOTE This command is executed automatically upon Pod reset Write Calibration Parameters CALn bbbb aaaa Write offset and scale calibration values for Y mX b calibration in two s complement hex as two four digit numbers The full equation for calibrated input to the A D is Y 4095 4095 a b X b The equation for calibrated DAC output is Y 4095 a b 4095 X b In both equations b is the number of counts below zero and a is the number of counts over full
25. g ACCES 1 0 PRODUCTS INC 10623 Roselle St San Diego CA 92121 1506 Tel 858 550 9559 FAX 858 550 7322 REMOTE DAS POD Model RA1216 USER MANUAL File MRA1216 Cf REMOTE DAS POD MODEL RA1216 USER MANUAL NOTICES The information in this document is provided for reference only ACCES I O Products Inc does not assume any liability arising out of the application or use of the information or products described herein This document may contain or reference information and products protected by copyrights or patents and does not convey any license under the patent rights of ACCES nor the rights of others Printed in USA Copyright 1999 by ACCES I O Products Inc 10623 Roselle Street San Diego CA 92121 All rights reserved REMOTE DAS POD MODEL RA1216 USER MANUAL TABLE OF CONTENTS INSTALLATION 223 2 8 cot ur ae Mee ea ana ee re Deo been 1 1 GDUINSTALLATION Gt er be Hain at 1 1 3 5 INCH DISKETTE INSTALLATION 22 Como nenn een ren 1 1 DIRECTORIES CREATED ON THE HARD DISK 0 1 2 CALIBRATION 3 gtd Coke oe Vet Reg Ge Deka eat tea le a re 1 4 HARDWARE INSTALLATION ct hatte are an en nee 1 5 INPUT OUTPUT CONNECTIONS 2 2 ied nn 1 6 50 bea vere ns ee Bal daeea hr 1 6 GETTING STARTED 2 2 2 44 84 re dade deeb halved donee ee a abe
26. iven program that assists you in configuring and calibrating your RA1216 The SETUP EXE program instructs you on the use of the serial opto isolation and DAC Offset jumpers and allows you to specify the Pod Address and the serial baud rate This program can also auto detect the address and or baud rate of an attached card in the host computer Finally a calibration procedure tests the unit and determines the calibration correction values and stores them into internal memory A sample program is provided to demonstrate the use of the calibration feature The Setup program should be run with only a single Pod attached to the RS 485 port in your computer You will need to know the setup information base address IRQ of the port so that the Setup program can access it The Setup program will create a batch file in its directory called RISC BAT that can be used to run RISCTerm RISCTerm This program provides a simple non automated interface to RS 485 devices and can be used to configure or test RA1216 setup and operations Context sensitive help on using RISCTerm is provided by pressing I DRIVERS COMMDRV PAS COMMDRV H and COMMDRV C are communication shortcuts or drivers provided and Pascal Three functions are provided initComCard writePod and readPod The functions are polling based no IRQ necessary and deal with strings rather than character by character Consult the source code files for more informatio
27. ment the same 3 byte parameter passed to the PL series of commands The channel specified in the parameter is acquired using the range polarity and MUX gain specified The data is returned immediately unlike the AC command Ann nn xxxx The A command works very similarly to the AC command All parameters are the same However the command runs the foreground occupying all of the attention of the Pod s microcontroller This yields higher throughput but sacrifices flexibility The Pod acquires data at its fastest possible rate Issue an R command to retrieve the data Configure Bits as Input or Output Mxx Configures digital bits as inputs or outputs Mx Configures digital bit x as output Mx Configures digital bit x as input These commands program the digital bits on a bit by bit basis as input or output A zero 3 7 REMOTE DAS POD MODEL RA1216 USER MANUAL in any bit position of the xx control byte designates the corresponding bit to be configured as an input Conversely a one designates a bit to be configured as an output Note Any bit configured as an output can still be read as an input if the current value output is a one Example Program even bits as outputs and odd bits as inputs SEND MAA RECEIVE CR Read Digital Inputs Read 7 bits In Read bit number n These commands read the digital input bits from the Pod All byte responses are sent most significant nybble first Exa
28. mples Read ALL 7 bits SEND RECEIVE FF CR Read only bit 2 SEND 12 RECEIVE 1 CR Write Digital Outputs Oxx Write to all 7 digital output bits Set bit x hi or low These commands write outputs to digital bits Any attempt to write to a bit configured as an input will fail Writing to a byte or word wherein some bits are input and some are output will cause the output latches to change to the new value but the bits that are inputs will not output the value until unless they are placed in output mode Single bit commands will return an error 4 if an attempt is made to write to a bit configured as an input Writing a one to a bit asserts the pull down for that bit Writing a zero de asserts the pull down Therefore if the factory default 5V pull up is installed writing a one will cause zero volts to be at the connector and writing a zero will cause 5 volts to be asserted Examples Write a one to bit 6 set output to zero volts assert the pull down SEND O6 RECEIVE CR 3 8 REMOTE DAS POD MODEL RA1216 USER MANUAL Write a zero to bit 2 set output to 5V or user pull up SEND O2 or SEND 002 RECEIVE CR Write zeros to bits 0 6 SEND 000 RECEIVE CR Write zeros to every odd bit SEND OAA RECEIVE CR Read Firmware Revision Number V Read the firmware revision number This command is used to read the version of firmware installed in the Pod It returns
29. n SAMPLE This program demonstrates reading and displaying A D channels and polling the Pod for general information The sample also demonstrates use of the driver and the software driven calibration procedure CALIBRATION The setup software provided with the RA1216 supports the ability to check calibration and to write correction values into EEPROM so they are available automatically on power up Calibration checks need only be performed periodically not every time power is cycled The SETUP EXE software calibration procedure requires the ability to ground an analog channel and provide a voltage source set at 5 000V and another for 0 250V The SAMPLE1 program illustrates the procedure of recalling these values and adjusting the readings The command descriptions of CALn CALn xxxx xxxx CAL BACKUP provide instructions on adding the calibration functions to your own software See the Software section for a description on calibrating the A D input and DAC output using the values from the calibration procedure 1 1 REMOTE DAS POD MODEL RA1216 USER MANUAL HARDWARE INSTALLATION The RA1216 enclosure is a sealed die cast aluminum alloy NEMA 4 enclosure that is easily mounted using two diagonal holes accessible when the cover is removed Outside dimensions of the enclosure are 8 74 long by 5 75 wide by 2 17 high The cover incorporates a recessed neoprene gasket and the cover is secured to the body by six recessed M 4 stainless ste
30. nates either a ora All commands are terminated with CR the ASCII character 13 All commands are not case sensitive i e upper or lower case may be used The symbol means zero or more valid characters total msg length lt 255 decimal Concepts Onboard Digital I O 3 1 REMOTE DAS POD MODEL RA1216 USER MANUAL The RA1216 has 7 digital inputs outputs The outputs are on the same pins as the inputs They comprise the DI O port Concepts The Point A Point as used in the RA1216 is a channel number and its associated gain Diff SE and offset settings The Point defines the A D channel number what gain should be applied whether it is single ended or differential and what setting is desired on the Offset DAC The format of the 3 byte Point is as follows ojo Offset DAC count value CAL 023 A typical Point might be 308800 which would translate to gain code 3 channel 0 single ended with zero volts on the Offset DAC see the Offset DAC section for more info GAIN GAIN BASE A D RANGE CODE Volts 2 0 25 0 1 2 3 10 0 0 5 4 5 40 0 0 125 6 7 The BASE A D RANGE column indicates the input range associated with each gain code assuming the offset DAC voltage is zero The offset DAC will shift this base range by the amount of voltage supplied Concepts The Point List Buffer Because each channel can be acquired at a different gain and
31. s the Pod to communicate at a new baud rate The parameter passed nnn is slightly unusual Each n is the same digit from the following table CODE BAUD RATE 1200 2400 4800 9600 14400 19200 28800 57600 Therefore valid values for the command s nnn are 000 111 222 333 444 555 666 or 777 The pod returns a message indicating it will comply The message is sent in the old baud rate not the new one Once the message is transmitted the Pod changes to the new baud rate The new baud rate is stored in EEPROM and will be used even after power reset until the next BAUD nnn command is issued Examples Set the Pod to 19200 baud SEND BAUD 555 RECEIVE Baud 05 CR Set the Pod to 9600 baud SEND BAUD 333 RECEIVE Baud 03 CR REMOTE DAS POD MODEL RA1216 USER MANUAL Configure Pod Address POD xx Program the currently selected Pod to respond at address xx This command changes the Pod s address to xx If the new address is 00 the Pod will be placed into non addressed mode If the new address is not 00 the Pod will not respond to further communications until a valid address command is issued Hex numbers 00 FF are considered valid addresses The RS 485 specification allows only 32 drops on the line so some addresses may be unused The new Pod address is saved in EEPROM and will be used even after power down until the next Pod xx command is issued Note that if the new address is not 00 i e the Pod
32. scale CAL entries 0 7 use the A D equation Entries 9 14 use the DAC equation 3 5 REMOTE DAS POD MODEL RA1216 USER MANUAL The Pod stores 16 calibration M b pairs one each for the 8 gain codes one for the Offset DAC one each for the 3 DACs at both Gains 6 total and one for the onboard Reference The following table shows the values for n for each calibration constant Entry number n Contains calibration constants for OAD GAIN 1 AD Gain 1 3 AD Gain 3 5 AD Gain 5 OAD GING 7 AD Gain 7 Poo OffsetDAC S O 9 DAC 0 Gain 0 0 5V 11 DAC 2 Gain 0 DAC 0 Gain 1 0 10V 13 DAC 1 Gain 1 14 15 DAC 2 Gain 1 Onboard Reference factory use This function stores the values required to adjust the measurement readings to agree with the last calibration The SETUP program will measure and write these calibration parameters The SAMPLE 1 program illustrates using CALn command with the results of this function Return Calibration Parameters CALn Recalls the scale and offset calibration constants for Y mX b calibration stored using the CALn xxxx xxxx command Set Sample Rate S XXXX Set Sample Rate of the A D Converter This function sets the sample rate of the A D converter Valid values range from 00A2 to FFFF The value passed is the desired divisor of the rate clock 11 0592 MHz The equation to use in calculating the divisor is Divisor 1 Rate 22 Clock 12 Examples Program the RA1216 for 1K s
33. umpers available to By Pass Opto Isolators if Desired and for Calibration Purposes Protective NEMA 4 Enclosure for Harsh Atmospheric and Marine Environments COMPUTER COMMUNICATIONS A type DS80C310 microcontroller with 32K x 8 bits SRAM 32K x 8 bits non volatile EEPROM and a watchdog timer circuit gives RA1216 the capability and versatility expected from a modern distributed control system RA1216 contains CMOS low power circuitry an optically isolated receiver transmitter and power conditioners for local and external isolated power The pod can operate at baud rates up to 57 6 K baud and distances up to 4000 feet with low attenuation twisted pair cabling such as Belden 9841 or equivalent Data collected by the pod can be stored in local SRAM and accessed later through the computer s serial port This facilitates a stand alone mode of operation All programming of RA1216 is in ASCll based software ASCll based programming is flexible because it permits you to write applications in any high level language that supports ASCII string functions You can use REMOTE ACCES Series pods with virtually any computer that has an RS 485 port The module or pod address is programmable from 00 to FF hex Whatever address is assigned is stored in EEPROM and used as the default address at the next Power ON Similarly the baud rate is programmable is stored in EEPROM and is used as the default at the next Power ON 2 1 REMOTE DAS POD MODEL R
34. utput Voltage unloaded Driver Output Voltage loaded LD and LDGND jumpers in Driver Output Resistance 500 Driver Output Short Circuit 150 mA Current Driver Output Rise Time 10 unit interval Receiver Sensitivity 200 mV Receiver Common Mode Voltage Range Receiver Input Resistance To prevent signal reflections in the cable and to improve noise rejection in both the RS 422 and RS 485 mode the receiver end of the cable should be terminated with a resistance equal to the characteristic impedance of the cable An exception to this is the case where the line is driven by an RS 422 driver that is never tri stated or disconnected from the line In this case the driver provides a low internal impedance that terminates the line at that end A 2 REMOTE DAS POD MODEL RA1216 USER MANUAL RS 485 DATA TRANSMISSION The RS 485 Standard allows a balanced transmission line to be shared in a party line mode As many as 32 driver receiver pairs can share a two wire party line network Many characteristics of the drivers and receivers are the same as in the RS 422 Standard One difference is that the common mode voltage limit is extended and is 12V to 7V Since driver can be disconnected or tri stated from the line it must withstand this common mode voltage range while in the tristate condition The following illustration shows a typical multidrop or party line network Note that the transmission line is terminated on
35. x 0 to 255 decimal Whatever address is assigned is stored in EEPROM and used as default at next Power On Asynchronous Data Format 7 data bits even parity one stop bit Input Common Mode Voltage 300V minimum opto isolated If opto isolators are by passed 7V to 12V Receiver Input Sensitivity 200 mV differential input Receiver Input Impedance 12KQ minimum Transmitter Output Drive 60 mA 100 mA short circuit current capability Serial Data Rates Programmable for 1200 2400 4800 9600 14400 19200 28800 and 57600 baud Crystal oscillator provided ANALOG INPUTS Channels Sixteen single ended with common ground or eight differential Voltage Ranges Software controllable Unipolar 0 5V 0 2 5V 0 1V 0 500 mV 0 250 mV 0 125 mV 0 50 mV and 0 25 mV Bipolar 2 5V 1 25V 500 mV 250 mV 62 5 mV 25 mV and 12 5 mV Current Range 4 20 mA across 2000 0 8 4V Input Protection 200 VDC Input Filter Low pass 10KQ 0 1UF Input Impedance 10 Megohms Resolution 12 binary bits Accuracy 0 025 1 LSB Gain Drift 5 PPM C Coding True binary for unipolar inputs and offset binary for bipolar inputs Throughput 50 000 conversions per second in foreground mode 6 67K conversions per second in background mode A D Type Successive Approximation Trigger Source Software command or on board programmable timer ANALOG OUTPUTS Channels Three independent Type 12 bit double buffered Non Linearity 0
36. y expressed or implied shall apply to any and all such equipment sold or furnished by ACCES 5 1 REMOTE DAS POD MODEL RA1216 USER MANUAL APPENDIX A APPLICATION CONSIDERATIONS INTRODUCTION Working with RS 422 and RS 485 devices is not much different from working with standard RS 232 serial devices and these two standards overcome deficiencies in the RS 232 standard First the cable length between two RS 232 devices must be short less than 50 feet at 9600 baud Second many RS 232 errors are the result of noise induced on the cables The RS 422 standard permits cable lengths up to 4000 feet and because it operates in the differential mode it is more immune to induced noise Connections between two RS 422 devices with CTS ignored should be as follows Device 1 Device 2 A third deficiency of RS 232 is that more than two devices cannot share the same cable This is also true for RS 422 but RS 485 offers all the benefits of RS 422 plus allows up to 32 devices to share the same twisted pairs An exception to the foregoing is that multiple RS 422 devices can share a single cable if only one will talk and the others will all receive BALANCED DIFFERENTIAL SIGNALS The reason that RS 422 and RS 485 devices can drive longer lines with more noise immunity than RS 232 devices is that a balanced differential drive method is used Ina balanced differential system the voltage produced by the driver appears across a pair of wires
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