SIM984 Isolation Amplifier - Stanford Research Systems
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1. 15 V 300 mA 24 V 100 mA TBD Serial RS 232 through SIM interface Connectors banana jack 2 front BNC 1 front 1 rear DB 15 male SIM interface Weight 1 5 lbs Dimensions 1 5 W x 3 6 H x 7 0 D ASRS SIM984 Isolation Amplifier 1 Getting Started This chapter gives you the necessary information to get started quickly with the SIM984 Isolation Amplifier In This Chapter 1 1 Introduction to the Instrument 1 2 Tally VOWORVIEW coo ine Ce a ee 1 2 1 1 2 Power on State 1 2 1 2 Front Panel Operation 1 2 L21 PUES s s es eea E E 1 2 III enos grege a a SPA aie aed Dee 1 2 1 2 3 Bandwidth 1 3 12 4 A are e gee ent a eae ae 1 3 1 3 SIM Interface ice oe a SR a eS 1 4 1 3 1 SIM interface connector 1 4 1 3 2 Direct interfacing A ARA 1 5 1 2 Getting Started 1 1 Introduction to the Instrument 1 1 1 Overview 1 1 2 Power on State The SIM984 Isolation Amplifier is a low noise programmable gain amplifier for isolating analog signals from DC to 1 MHz The basic function of the SIM984 is to isolate and possibly amplify an analog signal The input presents a 1 MOimpedance between the red and black banana jacks but is high impedance floating between each input jack and chassis ground A maximum of 1000 Vdc can be between either jack and ground but the potential betwee2. 2 2 Alphabetic List of Commands 23 Introductions 6 306929443 e Poe dada 2 4 Commands 0 000 eee eee ene 2 5 StatusModel 0 0 000000 2 3 Circuitry 3 1 Circuit Descriptions edad da 3 2 Schematic Diagrams 525 WB gn Ea Re aa ii Contents ASRS SIM984 Isolation Amplifier General Information The SIM984 Isolation Amplifier part of Stanford Research Systems Small Instrumentation Modules family is a wide bandwidth low noise isolation amplifier for use with analog signals from DC to 1 MHz Service Do not install substitute parts or perform any unauthorized modifi cations to this instrument The SIM984 is a single wide module designed to be used inside the SIM900 Mainframe Do not turn on the power until the module is completely inserted into the mainframe and locked in place iii iv General Information Symbols you may Find on SRS Products Alternating current Caution risk of electric shock Frame or chassis terminal Caution refer to accompanying documents Earth ground terminal 4 SRS SIM984 Isolation Amplifier General Information Notation A WARNING A CAUTION The following notation will be used throughout this manual A warning means that injury or death is possible if the instructions are not obeyed A caution means that damage to the instrument or other equipment is possible Typesetting conventions used in this manual
3. SRE i i Example Service Request Enable Set query the Service Request Enable register bit i to j SRE 0 1 CLS Example Clear Status CLS immediately clears the ESR CESR and the OVLD bit in the Status Byte CLS SIM984 Isolation Amplifier ASRS Remote Operation ESR i Example Standard Event Status Reads the Standard Event Status Register bit i Upon executing ESR the returned bit s of the ESR register are cleared ESR 64 ESE 11 4 Example Standard Event Status Enable Set query the Standard Event Status Enable Register bit i to j ESE 6 1 ESE 64 CESR i Example Comm Error Status Query Comm Error Status Register for bit Upon executing a CESR query the returned bit s of the CESR register are cleared CESR 0 CESE 1 101 Example Comm Error Status Enable Set query Comm Error Status Enable Register for bit i to j CESE 0 OVLD Example Overload Condition Query Overload Condition If the SIM984 is overloading OVLD returns 1 otherwise 0 OVLD 0 ASRS SIM984 Isolation Amplifier 2 4 Commands PSTA 2 Example Pulse STATUS Mode Set query the Pulse STATUS Mode to Z OFF 0 ON 1 When PSTA ON is set any new service request will only pulse the STATUS signal low for a minimum of 1 us The default behavior is to latch STATUS low until a
4. STB query is received At power on PSTA is set to OFF PSTA OFF 2 4 6 Interface Commands Interface commands provide generic control over the interface be tween the SIM984 and the host computer RST Example Reset Reset the SIM984 to default configuration After RST the gain is set to x1 and the bandwidth to DC 100 Hz This is equivalent to the following command sequence GAIN 0 BWTH 0 RST IDN Example Identify Read the device identification string The identification string is formatted as Stanford Research Systems SIM984 s n ver where is the 6 digit serial number and is the firmware revision level IDN Stanford_Research_Systems SIM984 s n003075 ver1 02 OPC Example Operation Complete Operation Complete Sets the OPC flag in the ESR register The query form OPC writes a 1 in the output queue when complete but does not affect the ESR register OPC SIM984 Isolation Amplifier SRS Remote Operation Console Mode Set query the Console mode to Z OFF 0 ON 1 CONS causes each character received at the Input Buffer to be copied to the Output Queue At power on and Device Clear CONS is set to OFF Example CONS 0 LEXE Execution Error Query the last execution error code A query of LEXE always clears the error code so a subsequent LEXE will return 0 Valid codes are Value Definition 0 No execution erro
5. and are not always required Parameters in are required to set a value and are omitted for queries Parameters in are optional in both set and query commands Parameters listed without any surrounding characters are always required Do not send or or as part of the command Multiple parameters are separated by commas Multiple commands may be sent on one command line by separating them with semi colons so long as the input buffer does not overflow Commands are terminated by either CR or LF characters Null commands and whitespace are ignored Execution of command s does not begin until the command terminator is received Token parameters generically shown as Z in the command de scriptions can be specified either as a keyword or integer value Command descriptions list the valid keyword options with each keyword followed by its corresponding integer value For example to set the response termination sequence to CR lt LF the following two commands are equivalent TERM CRLF or TERM 3 For queries that return token values the return format keyword or integer is specified with the TOKN command SIM984 Isolation Amplifier ASRS 2 6 Remote Operation 2 4 2 Notation 2 4 3 Examples The following table summarizes the notation used in the command descriptions symbol definition ij Integers Z Literal token Required for queries illegal for set commands var p
6. are e Front panel buttons are set as Button e Front panel indicators are set as Overload e Remote command names are set as IDN e Literal text other than command names is set as OFF Remote command examples will all be set in monospaced font In these examples data sent by the host computer to the SIM984 are set as straight teletype font while responses received by the host computer from the SIM984 are set as slanted teletype font SIM984 Isolation Amplifier ASRS vi General Information Specifications Performance Characteristics Isolation voltage Leakage current Isolation capacitance Isolation Mode Rejection Ratio IMRR Maximum input Input impedance Input noise typ Input offset drift 1000 V max lt 2 uA at 1000 Vdc 1000 pF 150 dB at DC 10V 1MO 15 nV vVHz 1 kHz 3 wV C typ Output voltage range Output current Output resistance Output offset Output offset drift Output noise typ 10V 20 mA max 500 0 1 V adjustable 1mVC typ 80 uVrms 100 Hz bandwidth 200 uVrms 10 kHz bandwidth 1 5mVrms 1 MHz bandwidth Gain Gain accuracy THD Frequency range Output Slew rate x 1 x 10 x 100 0 5 0 005 1 kHz 600 Q load DC to 100 Hz low BW DC to 10 kHz medium BW DC to 1 MHZ high BW 25 V us Vout 20 Vpp Operating temperature Power General Characteristics Interface 0 C to 40 C non condensing 5 V 100 mA
7. clears only bit i SIM984 Isolation Amplifier SRS Remote Operation Weight Bit Flag 1 0 PARITY 2 1 FRAME 4 2 NOISE 8 3 HWOVRN 16 4 OVR 32 5 RTSH 64 6 CTSH 128 7 DCAS PARITY FRAME NOISE HWOVRN OVR RTSH CTSH DCAS Parity Error Set by serial parity mismatch on incoming data byte Framing Error Set when an incoming serial data byte is missing the STOP bit Noise Error Set when an incoming serial data byte does not present a steady logic level during each asynchronous bit period window Hardware Overrun Set when an incoming serial data byte is lost due to internal processor latency Causes the Input Buffer to be flushed and resets the command parser Input Buffer Overrun Set when the Input Buffer is overrun by incoming data Causes the Input Buffer to be flushed and resets the command parser Undefined for the SIM984 Undefined for the SIM984 Device Clear Indicates the SIM984 received the Device Clear signal an RS 232 break Clears the Input Buffer and Output Queue and resets the command parser 2 5 6 Communication Error Status Enable CESE The CESE acts as a bitwise AND with the CESR register to produce the single bit CESB message in the Status Byte Register SB It can be set and queried with the CESE command This register is cleared at power on ASRS SIM984 Isolation Amplifier 3 Circuits This chapter presents a brief
8. gain is applied The SIM984 is controlled by microcontroller U107 A critical aspect of the design is the clock stop circuitry implemented by U102 and U105 A simple RC oscillator is enabled or disabled at pin 1 of U102 which is driven by synchronizing flip flop U105B to ensure that no runt clock pulses are produced that would violate U107 s minimum clock periods Four separate clock starting signals are combined by U106 e Power on reset e Amplifier overload e Incoming serial data e Front panel button press ASRS SIM984 Isolation Amplifier 3 2 Schematic Diagrams 3 3 The fast start time of the RC oscillator ensures that incoming se rial data will be correctly decoded by the microcontroller s UART even when the clock is started by the serial start bit of the incoming data When the microcontroller has completed all pending activity it drives the STOP signal high pin 71 of U107 effectively halting its own processor clock In this way the SIM984 guarantees no digital clock artifacts can be generated during quiescent operation 3 2 Schematic Diagrams Schematic diagrams follow this page SIM984 Isolation Amplifier ASRS
9. status model When masked by the Service Request Enable register a bit set in the Status Byte causes the STATUS signal to be asserted on the rear panel SIM interface connector Typically STATUS remains asserted low until a STB query is received at which time STATUS is deasserted raised After clear ing the STATUS signal it will only be re asserted in response to a 1 but see the PSTA command Communication Error Status Standard Event Status PON Power On 7 URQ User Request CME Command Error EXE Execution Error DDE Device Error QYE Query Error INP Input Buffer Error OPC Operation Complete Status Byte L gt CESB mies STATUS ESB IDLE undef e 8 e s Lel le m an a m un m undef undef OVLD e s 4 xs siel lel n D m Figure 2 1 Status Register Model for the SIM984 SIM984 Isolation Amplifier SRS 2 14 Remote Operation new status generating condition Weight Bit Flag 1 0 OVLD 2 1 undef 0 4 2 undef 0 8 3 undef 0 16 4 IDLE 32 5 ESB 64 6 MSS 128 7 CESB OVLD Overload Bit Indicates whether an amplifier overload has occurred IDLE Indicates that the Input Buffer is empty and the command parser is idle Can be used to help synchronize SIM984 qu
10. 2 15 2 5 4 Standard Event Status Enable ESE 2 15 2 5 5 Communication Error Status CESR 2 15 2 5 6 Communication Error Status Enable CESE 2 16 2 2 Remote Operation 2 1 Index of Common Commands symbol definition ij Integers Z Literal token Required for queries illegal for set commands var parameter always required var required parameter for set commands illegal for queries var optional parameter for both set and query forms Amplifier GAIN i 2 7 Gain BWTH i 2 7 Bandwidth Status STB 1 2 7 Status Byte SRE i j 2 7 Service Request Enable CLS 2 7 Clear Status ESR i 2 8 Standard Event Status ESE 1 1 j 2 8 Standard Event Status Enable CESR i 2 8 Comm Error Status CESE i j 2 8 Comm Error Status Enable OVLD 2 8 Overload Condition PSTA z 2 9 Pulse STATUS Mode Interface Ret 2 9 Reset IDN 2 9 Identify OPC 2 9 Operation Complete CONS z 2 10 Console Mode LEXE 2 10 Execution Error LCME 2 11 Command Error PARI z 2 11 Parity TOKN 2 2 11 Token Mode TERM z 2 12 Response Termination ASRS SIM984 Isolation Amplifier 2 2 Alphabetic List of Commands 2 2 Alphabetic List of Commands CLS 2 7 Clear Status ESE 1 1 j 2 8 Standard Event Status Enable ESR 1 2 8 Standard Event Status IDN 2 9 Identify OPC 2 9 Operation Complete RST 2 9 Reset SRE i j 2 7 S
11. 84 Isolation Amplifier SRS Remote Operation Example Response Termination Set query the term sequence to Z NONE 0 CR 1 LF 2 CRLF 3 LFCR 4 The term sequence is appended to all query responses sent by the module and is constructed of ASCII character s 13 car riage return and 10 line feed The token mnemonic gives the sequence of characters At power on TERM is set to CRLF TERM 3 ASRS SIM984 Isolation Amplifier 2 5 Status Model 2 13 2 5 Status Model The SIM984 status registers follow the hierarchical IEEE 488 2 for mat A block diagram of the status register array is given in Figure 2 1 There are two categories of registers in the SIM984 status model Event Registers These read only registers record the occurrence of defined events When the event occurs the corresponding bit is set to 1 Upon querying an event register any set bits within it are cleared These are sometimes known as sticky bits since once set a bit can only be cleared by reading its value Event register names end with SR Enable Registers These read write registers define a bitwise mask for their cor responding event register If any bit position is set in an event register while the same bit position is also set in the enable register then the corresponding summary bit message is set Enable register names end with SE 2 5 1 Status Byte SB The Status Byte is the top level summary of the SIM984
12. Operation and Service Manual Isolation Amplifier SIM984 SRS Stanford Research Systems Revision 1 12 e March 5 2013 Certification Stanford Research Systems certifies that this product met its published specifications at the time of shipment Warranty This Stanford Research Systems product is warranted against defects in materials and workman ship for a period of one 1 year from the date of shipment Service For warranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this document is subject to change without notice Copyright Stanford Research Systems Inc 2013 All rights reserved Stanford Research Systems Inc 1290 D Reamwood Avenue Sunnyvale CA 94089 USA Phone 408 744 9040 e Fax 408 744 9049 www thinkSRS com e e mail info thinkSRS com Printed in U S A Document number 9 01691 903 4 SRS SIM984 Isolation Amplifier Contents General Information ON MPO S Dio a e amp ee ee ee ae Gee cing Notations ii amp a Dae 2 Bake A ee Pe Pee ae Specifications laa a dale eid tee wd 1 Getting Started 1 1 Introduction to the Instrument 1 2 Front Panel Operation ook a oa ee Rs 1 3 SiMinterface 2 Remote Operation 2 1 Index of Common Commands
13. arameter always required var required parameter for set commands illegal for queries var optional parameter for both set and query forms Each command is provided with a simple example illustrating its usage In these examples all data sent by the host computer to the SIM984 are set as straight teletype font while responses received the host computer from the SIM984 are set as slanted teletype font The usage examples vary with respect to set query optional param eters and token formats These examples are not exhaustive but are intended to provide a convenient starting point for user program ming ASRS SIM984 Isolation Amplifier 2 4 Commands 2 4 4 Amplifier Commands GAIN i Gain Set query input gain to state 0 x1 1 x10 2 x100 GAIN 2 BWTH i Bandwidth 2 4 5 Status Commands Example Set query the signal bandwidth to state 0 DC 100 Hz 1 DC 10 kHz 2 DC 1 MHz BWTH 1 The Status commands query and configure registers associated with status reporting of the SIM984 STB 1 Example Status Byte Reads the Status Byte register bit Execution of the STB query without the optional bit i always causes the STATUS signal to be deasserted Note that STB i will not clear STATUS even if bit i is the only bit presently causing the STATUS signal See also the PSTA command The OVLD bit in STB is cleared upon reading STB 1
14. description of the SIM984 circuit design In This Chapter 3 1 Circuit Descriptions iain Se ad dr 3 2 3 1 1 Isolated power ex orar a aM 3 2 3 1 2 Input amplifier uri o ee AO 3 2 3 1 3 Output circuitry Seg eA 3 2 3 1 4 Digital control va 3 2 3 2 Schematic Diagrams 3 3 3 2 Circuitry 3 1 Circuit Descriptions 3 1 1 Isolated power 3 1 2 Input amplifier 3 1 3 Output circuitry 3 1 4 Digital control Page 3 of the schematics shows the isolated supply that powers the input stage A spread spectrum oscillator U302 provides the AC drive signal for power amplifier U301 to drive the isolating trans former T301 The large capacitor C305 prevents any runaway DC current from saturating the transformer which could be generated by offset voltages at U301 The upper portion of Page 2 shows the floating input amplifier Gain is controlled through latching relays U214 and U215 the control coils of which are earth referenced The amplified signal is optically coupled through U205 U206 U207 and U208 The earth referenced output circuitry includes the output band width control This circuitry is on the lower portion of Page 2 of the schematics The overall AC gain is trimmed using VR202 at the factory and should not require user adjustment DC offset can be adjusted with VR203 accessed from the front panel of the instrument Note that the offset trim is referenced to the output and comes after the
15. ervice Request Enable STB 1 2 7 Status Byte B BWTH i 2 7 Bandwidth C CESE i j 2 8 Comm Error Status Enable CESR i 2 8 Comm Error Status CONS z 2 10 Console Mode G GAIN i 2 7 Gain L LCME 2 11 Command Error LEXE 2 10 Execution Error O OVLD 2 8 Overload Condition P PARI z 2 11 Parity PSTA z 2 9 Pulse STATUS Mode T TERM z 2 12 Response Termination TOKN 2 2 11 Token Mode SIM984 Isolation Amplifier ASRS 2 4 Remote Operation 2 3 Introduction Remote operation of the SIM984 is through a simple command lan guage documented in this chapter Both set and query forms of most commands are supported allowing the user complete control of the isolation amplifier from a remote computer either through the SIM900 Mainframe or directly via RS 232 see Section 1 3 2 1 2 3 1 Power on configuration 2 3 2 Buffers 2 3 3 Device Clear 2 4 Commands The settings for the remote interface are 9600 baud with no parity and no flow control and local echo disabled CONS OFF Most of the SIM984 instrument settings are stored in non volatile memory and at power on the instrument returns to the state it was last in when power was removed Exceptions are noted in the com mand descriptions Reset values of parameters are shown in boldface Incoming data from the host interface is stored in a 32 byte input buffer Characters accumulate in the input buffer until a com
16. ery responses ESB Event Status Bit Indicates whether one or more of the enabled events in the Standard Event Status Register is true MSS Master Summary Status Indicates whether one or more of the enabled status messages in the Status Byte register is true Note that while STATUS is released by the STB query MSS is only cleared when the underlying enabled bit message s are cleared CESB Communication Error Summary Bit Indicates whether one or more of the enabled flags in the Communication Error Status Register has become true Most bits in the Status Byte are not cleared by the STB query These bits are only cleared by reading the underlying event registers or by clearing the corresponding enable registers The one exception is the OVLD bit which itself is an event bit and so is cleared by the STB query 2 5 2 Service Request Enable SRE Each bit in the SRE corresponds one to one with a bit in the SB register and acts as a bitwise AND of the SB flags to generate the MSS bit in the SB and the STATUS signal Bit 6 of the SRE is undefined setting it has no effect and reading it always returns 0 This register is set and queried with the SRE command This register is cleared at power on 4 SRS SIM984 Isolation Amplifier 2 5 Status Model 2 5 3 Standard Event Status ESR The Standard Event Status register consists of 8 event flags These event flags are all sticky bits that are set by the co
17. ith the PARI command 1 Although the serial interface lines on the DB 15 do not satisfy the minimum voltage levels of the RS 232 standard they are typically compatible with desktop SIM984 Isolation Amplifier personal computers SRS 1 6 Getting Started DB 15 F to SIM984 Name DB 9 F 10 3 TxD 11 2 RxD 5 Computer Ground to P S 7 lt 15VDC 13 5VDC 14 15VDC 15 24VDC 8 9 lt Ground P S return current 1 Signal Ground separate wire to Ground Table 1 2 SIM984 Direct Interface Cable Pin Assignments 4 SRS SIM984 Isolation Amplifier 2 Remote Operation In This Chapter This chapter describes operating the SIM984 over the serial interface 2 1 2 2 2 3 2 4 2 5 Index of Common Commands 2 2 Alphabetic List of Commands 2 3 Introduction seese Be ed Es 2 4 2 3 1 Power on configuration 2 4 23 2 Buffers ia ad Ble ED ape es 2 4 2 3 3 Device Clear 2 4 COMMAandsS s s e aae ade Be ae a 2 4 2 4 1 Command Syntax od o id 2 5 242 Notation ce ee 2 6 243 Examples secaos e e a da E OG 2 6 2 44 Amplifier Commands 2 7 2 4 5 Status Commands 2 7 2 4 6 InterfaceCommands 2 9 Status Model iia ea e ii is 2 13 251 Stat s Byt SB crer ele BAS Cees 2 13 2 5 2 Service Request Enable SRE 2 14 2 5 3 Standard Event Status ESR
18. mand terminator either CR or LF is received at which point the mes sage is parsed and executed Query responses from the SIM984 are buffered in a 32 byte output queue If the input buffer overflows then all data in both the input buffer and the output queue are discarded and an error is recorded in the CESR and ESR status registers The SIM984 host interface can be asynchronously reset to its power on configuration by sending an RS 232 style break signal From the SIM900 Mainframe this is accomplished with the SIM900 SRST command if directly interfacing via RS 232 then use a serial break signal After receiving the Device Clear the interface is reset and CONS mode is turned OFF Note that this only resets the communi cation interface the basic function of the SIM984 is left unchanged to reset the instrument see RST This section provides syntax and operational descriptions for reo mote commands ASRS SIM984 Isolation Amplifier 2 4 Commands 2 4 1 Command Syntax tokens The four letter mnemonic shown in CAPS in each command se quence specifies the command The rest of the sequence consists of parameters Commands may take either set or query form depending on whether the character follows the mnemonic Set only commands are listed without the query only commands show the after the mnemonic and optionally query commands are marked with a Parameters shown in
19. n the input jacks must be less than 10 V The input is DC coupled A gain of X1 x10 or X100 can be set from the front panel The output bandwidth is also adjustable from the front panel with three choices of high frequency cut off 100 Hz 10 kHz and 1MHz Finally the output DC offset can be trimmed using a thin screwdriver accessing the Offset hole near the output BNC The SIM984 stores its operation state gain and bandwidth configu ration in non volatile memory At power on the SIM984 will return to its previous configuration after a brief system check and initializa tion 1 2 Front Panel Operation 1 2 1 Inputs A WARNING 1 2 2 Gain The front panel of the SIM984 see Figure 1 1 provides a simple operator interface The input to the SIM984 is through the red and black banana jacks in the front panel INPUT block The banana jacks are isolated from the chassis for use with insulated test leads If the user connects a BNC to Banana adaptor to the SIM984 to allow inputs from a BNC terminated cable it is critical that no dangerous voltages be applied to the cable as the exposed shield of the input BNC could create an electrical hazard User gain settings of x1 x10 and x100 are selected with the left and right Gain buttons ASRS SIM984 Isolation Amplifier 1 2 Front Panel Operation 1 3 SRS SIM984 Isolation Amplifier BANDWIDTH a B E 106 19 1 O O Hz kHz MHz OUTPUT Off
20. plication of power may cause circuit damage SRS recommends using the SIM984 together with the SIM900 Mainframe for most applications SIM interface connector The DB 15 SIM interface connector carries all the power and commu nications lines to the instrument The connector signals are specified in Table 1 1 Direction Pin Signal Src gt Dest Description 1 SIGNALGND ME SIM Ground reference for signal 2 STATUS SIM gt MF Status service request GND asserted 5 V idle 3 RTS MF SIM HW handshake not used in SIM984 4 CTS SIM MF HW handshake not used in SIM984 5 REF 10MHZ MF SIM 10 MHz reference no connection in SIM984 6 5V MF SIM Power supply no connection in SIM984 7 15V MF gt SIM Power supply 8 PSRIN MF SIM Power supply return 9 CHASSIS GND Chassis ground 10 TXD MF gt SIM Async data start bit 0 5 V 1 GND 11 RXD SIM gt MF Async data start bit 0 5 V 1 GND 12 REF_10MHz MF SIM 10 MHz reference no connection in SIM984 13 5V MF gt SIM Power supply 14 15V MF gt SIM Power supply 15 24V MF SIM Power supply Table 1 1 SIM Interface Connector Pin Assignments DB 15 ASRS SIM984 Isolation Amplifier 1 3 SIM Interface 1 3 2 Direct interfacing 1 3 2 1 Direct interface cabl 1 3 2 2 Serial settings The SIM984 is intended for operation in the SIM900 Mainframe but users may wish to direc
21. r since last LEXE 1 Illegal value 2 Wrong token 3 Invalid bit 16 Command not ready Example STB 12 LEXE LEXE 3 0 The error 3 Invalid bit is because STB only allows bit specific queries of 0 7 The second read of LEXE returns 0 ASRS SIM984 Isolation Amplifier 2 4 Commands 2 11 LCME Command Error Query the last command error code A query of LCME always clears the error code so a subsequent LCME will return 0 Valid codes are Value Definition No execution error since last LCME Illegal command Undefined command Illegal query Illegal set Missing parameter s Extra parameter s Null parameter s Parameter buffer overflow Bad floating point 10 Bad integer 11 Bad integer token 12 Bad token value 13 Bad hex block 14 Unknown token CNaA dF WNF O NO Example IDN LCME 4 The error 4 Illegal set is due to the missing PARI z Parity Set query parity to z NONE ODD 1 EVEN 2 MARK 3 SPACE 4 After power on modules default to PARI NONE Example PARI EVEN TOKN z Token Mode Set query the Token Query mode to Z OFF 0 ON 1 If TOKN ON is set then queries to the SIM module that return to kens will return the text keyword otherwise they return the decimal integer value Thus the only possible responses to the TOKN query are ON and 9 On reset TOKN is set to OFF Example TOKN OFF SIM9
22. rresponding event and cleared only by reading or with the CLS command Reading a single bit with the ESR i query clears only bit i Weight Bit Flag 1 0 OPC 2 1 INP 4 2 OYE 8 3 DDE 16 4 EXE 32 5 CME 64 6 URO 128 7 PON OPC INP OYE DDE EXE CME URO PON Operation Complete Set by the OPC command Input Buffer Error Indicates data has been discarded from the Input Buffer Query Error Indicates data in the Output Queue has been lost Device Dependent Error This bit is undefined in the SIM984 Execution Error Indicates an error in a command that was successfully parsed Out of range parameters are an example The error code can be queried with LEXE Command Error Indicates a parser detected error The error code can be queried with LCME User Request Indicates a front panel button was pressed Power On Indicates that an off to on transition has occurred 2 5 4 Standard Event Status Enable ESE The ESE acts as a bitwise AND with the ESR register to produce the single bit ESB message in the Status Byte Register SB It can be set and queried with the ESE command This register is cleared at power on 2 5 5 Communication Error Status CESR The Communication Error Status register consists of 8 event flags each of which is set by the corresponding event and cleared only by reading or with the CLS command Reading a single bit with the CESR i query
23. set Figure 1 1 The SIM984 front and rear panels 1 2 3 Bandwidth User bandwidth settings of DC 100 Hz DC 10 kHz and DC 1 MHz are with the left and right Bandwidth buttons 1 2 4 Output The amplified band limited signal appears at the ground referenced BNC connectors on the front and rear panels Each output connec tion is through a 50 Q resistor For normal operation the user should not need to terminate the output If a 500 termination is applied the output signal will be divided in half If the output signal exceeds 10 V the output overload detection is activated This is indicated by the red OVLD near the top of the OUTPUT block on the front panel The SIM984 output offset voltage may be trimmed by adjusting the SIM984 Isolation Amplifier SRS Getting Started 1 3 SIM Interface A CAUTION 1 3 1 output offset through the front panel access hole in the OUTPUT block The primary connection to the SIM984 Isolation Amplifier is the rear panel DB 15 SIM interface connector Typically the SIM984 is mated to a SIM900 Mainframe via this connection either through one of the internal Mainframe slots or the remote cable interface It is also possible to operate the SIM984 directly without using the SIM900 Mainframe This section provides details on the interface The SIM984 has no internal protection against reverse polarity missing supply or overvoltage on the power supply pins Misap
24. tly interface the module to their own systems without the use of additional hardware The mating connector needed is a standard DB 15 receptacle such as Amp part 747909 2 or equivalent Clean well regulated sup ply voltages of 15 5 and 24 VDC must be provided following the pin out specified in Table 1 1 Ground must be provided on pins 1 and 8 with chassis ground on pin 9 The STATUS signal may be monitored on pin 2 for a low going TTL compatible output indicating a status message ing If the user intends to directly wire the SIM984 independent of the SIM900 Mainframe communication is usually possible by directly connecting the appropriate interface lines from the SIM984 DB 15 plug to the RS 232 serial port of a personal computer Connect RXD from the SIM984 directly to RD on the PC TXD directly to TD In other words a null modem style cable is not needed To interface directly to the DB 9 male DTE RS 232 port typically found on personal computers a cable must be made with a female DB 15 socket to mate with the SIM984 and a female DB 9 socket to mate with the PC s serial port Separate leads from the DB 15 need to go to the power supply making what is sometimes know as a hydra cable The pin connections are given in Table 1 2 The initial serial port settings at power on are 9600 Baud 8 bits no parity 1 stop bit and no flow control The serial baud rate and word size are fixed but the parity may be changed w
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