Manual - StanTronic Instruments
Contents
1. 5 14 2013 162. 6 2 Device Mode In Device mode Prologix GPIB USB Controller acts as another peripheral on the GPIB bus In this mode the controller can act as a GPIB TALKER or GPIB LISTENER only Since Prologix GPIB USB Controller is not the Controller In Charge while in this mode it expects to recetve commands from a GPIB controller When Device mode is enabled Prologix GPIB USB controller configures itself as a GPIB Listener All data received by the controller over the GPIB port is passed along to the USB port without buffering All data received from the host over USB is buffered until the GPIB controller addresses Prologix GPIB USB controller to talk at which time the buffered data is passed along to the GPIB port The controller can buffer only one command A subsequent command received over USB will overwrite the previously buffered one if the previous one has not yet been transmitted over GPIB Device mode is used to download screen plots from the instrument front panel for rendering using plotter emulation software 7 Data Transmission In Controller and Device modes characters received over USB port are aggregated in an internal buffer and interpreted when a USB termination character CR ASCII 13 or LF ASCII 10 is received If CR LF ESC ASCII 27 or ASCII 43 characters are part of USB data they must be escaped by preceding them with an ESC character All un escaped LF CR and ESC and characters in USB data are
3. 12 mode This command configures the Prologix GPIB USB controller to be a CONTROLLER ot DEVICE If the command is issued without any arguments the current mode is returned SYNTAX mode 0 1 where 1 CONTROLLER 0 DEVICE MODES AVAILABLE CONTROLLER DEVICE EXAMPLES mode 1 Switch to CONTROLLER mode mode 0 Switch to DEVICE mode mode Query current mode 8 13 read This command can be used to read data from an instrument until EOI is detected or timeout expires A specified character is read or timeout expires or e Timeout expires Timeout is set using the read_tmo_ms command and applies to inter character delay i e the delay since the last character was read Timeout is not be confused with the total time for which data is read SYNTAX read eo1 lt gt where lt char gt is a decimal value less than 256 MODES AVAILABLE CONTROLLER EXAMPLES read Read until timeout read eoi Read until EOI detected or timeout 5 14 2013 12 Prologix GPIB USB Controller User Manual read 10 Read until LF ASCII 10 is received or timeout 8 14 tread_tmo_ms This command specifies the timeout value in milliseconds to be used in the read command and spoll command Timeout may be set to any value between 1 and 3000 milliseconds SYNTAX read_tmo_ms lt time gt where lt time gt is decimal value between 1 and 3000 MODES AVAILABLE CONTROLLER 8 15 rst This command performs a power
4. discarded 5 14 2013 6 Prologix GPIB USB Controller User Manual As mentioned earlier an un escaped CR or LF acts as the USB terminator The terminating CR or LF is removed and GPIB termination characters specified by eos command are appended before transmitting data to instruments Any USB input that starts with the unescaped character sequence is interpreted as a controller command and not transmitted over GPIB When configured to do so using the auto command or the read command characters received from instruments are transmitted to host Unlike while sending data to instruments no character substitution is performed The firmware buffers only one character The FTDI USB driver provides additional buffering of about 4KB If a device is talking and the buffers firmware s and driver s are full the device continues to be in TALK mode but is stopped from further sending data using GPIB handshaking The eot_char command may be used to detect GPIB EOI signal assertion 71 Binary Data Transmission Prologix GPIB USB controller can send and receive binary data to and from GPIB enabled instruments No special action is necessary to receive binary data from instruments Any binary data received from the instrument is transmitted over USB to PC unmodified just as with ASCII data Since binary data from instruments is not usually terminated by CR or LF characters as is usually the case with ASCII data you m
5. EOI assertion with last character eoi 0 Disable EOI assertion eoi Query if EOI assertion is enabled or disabled 8 5 eos This command specifies GPIB termination characters When data from host is recetved over USB all non escaped LF CR and ESC characters are removed and GPIB terminators as specified by this command are appended before sending the data to instruments This command does not affect data from instruments received over GPIB port If the command is issued with no arguments then the current configuration is returned SYNTAX eos 0 1 2 3 where 0 CR LF 1 CR 2 LF 3 None MODES AVAILABLE CONTROLLER DEVICE EXAMPLES eos 0 Append CR LF to instrument commands eos 1 Append CR to instrument commands 2 Append LF to instrument commands eos 3 Do not append anything to instrument commands eos Query current EOS state 8 6 eot_enable This command enables or disables the appending of a user specified character see eot_char to USB output whenever EOI is detected while reading a character from the GPIB port If the command is issued without any argument the current state of eot_enable is returned SYNTAX eot_enable 0 1 MODES AVAILABLE CONTROLLER DEVICE EXAMPLES eot_enable 1 Append user defined character when EOI detected eot_enable 0 Do not append character when EOI detected eot_enable Query current eot_enable state 5 14 2013 10 Prologix GPIB USB Controller User M
6. PIB USB controller to a computer using USB A B cable 3 Install drivers according to instructions in www ftdichip com Documents InstallGuides htm 4 Plug controller directly or using a GPIB cable to the GPIB connector on the instrument Two kinds of drivers are available Virtual COM Port VCP driver and Direct D2XX driver The VCP driver emulates a standard serial port on the host computer such that the Prologix GPIB USB computer can be communicated with as a standard serial RS 232 device D2XX driver allows direct access to the controller via a DLL interface 3 Firmware Upgrade Prologix GPIB USB controller firmware is field upgradeable Latest firmware and upgrade installations are available at prologix biz 4 Host Software A wide variety of host software may be used to communicate with Prologix GPIB USB controller Terminal programs any terminal emulation program such as HyperTerminal Tera Term Pro or Minicom can be used to communicate with the controller and instruments connected to it 5 14 2013 4 Prologix GPIB USB Controller User Manual Custom applications any programming language or environment that provides access to serial ports if using VCP driver or allows interfacing to DLL if using D2XX driver may be used to develop custom applications Graphical programming environments like National Instruments LabView and Agilent VEE may be used as well EZGPIB an easy to use programming environment devel
7. PROLOGIX GPIB USB CONTROLLER USER MANUAL VERSION 6 107 May 14 2013 PROLOGIX BIZ Prologix GPIB USB Controller User Manual Table of Contents Ley AO a tai 4 2 O 4 Dy Biar A IA Ao 4 4 ei ieee heat aut Ren ha ashok Gib Lee ROR 4 De OA iia AS aval AAA 5 Operatie essa ni 5 bd Controller Mode nnna 5 6 2 Device Moderna na naaa dd A A hive 6 Te Data Eta ii 6 Tlr A Data TES 7 Sic COI 8 MG AA 8 92 TAO RINA ATA A AA A A O 8 SPR O ONE 9 84 A O ROA E N A A A TIA 9 O NO 10 8 6 0 BEA DT 1 D A 10 o ANE A 11 SS AN 11 O 11 8 10 a as 11 8 11 A A AE 11 8 12 aos 12 8 13 POAC Mastic oa ba 12 8 14 fread tmo MS da 13 8 15 E 13 8 16 O 13 8 17 pola leida india 14 8 18 BAUR nn OT 14 8 19 Ane EES EAEE tl aha siSe a eit eae 14 8 20 oa aaa 15 8 21 15 8 22 DOS AA ODO 15 Dis TO PECICA ORS IN AO NOS 15 5 14 2013 2 Prologix GPIB USB Controller User Manual Change Log May 14 2013 Added llo command description April 18 2011 Added lon command description Sept 14 2009 Added savecfg command descripion Corr
8. anual 8 7 eot_char This command specifies the character to be appended to USB output when eot_enable is set to 1 and is detected If the command is issued without any argument the currently specified character is returned SYNTAX eot_char lt char gt where lt char gt is a decimal value less than 256 MODES AVAILABLE CONTROLLER DEVICE EXAMPLES eot_char 42 Append ASCII 42 when is detected eot_char Query currently configured eot_char 8 8 This command asserts GPIB IFC signal for 150 microseconds making Prologix GPIB USB controller the Controller In Charge on the GPIB bus SYNTAX ifc MODES AVAILABLE CONTROLER 8 9 llo This command disables front panel operation of the currently addressed instrument SYNTAX llo MODES AVAILABLE CONTROLLER 8 10 loc This command enables front panel operation of the currently addressed instrument SYNTAX loc MODES AVAILABLE CONTROLLER 8 11 lon This command configures the GPIB USB controller to listen to all traffic on the GPIB bus irrespective of the currently specified address This configuration is also known as listen only mode In this mode the controller can only receive but cannot send any data 5 14 2013 11 Prologix GPIB USB Controller User Manual SYNTAX lon 0 1 MODES AVAILABLE DEVICE EXAMPLES lon 1 Enable listen only mode lon 0 Disable listen only mode lon Query listen only mode 8
9. ay want to use the eot_enable command to detect EOI indicating end of data See eot_enable command help for more details Special care must be taken when sending binary data to instruments If any of the following characters occur in the binary data CR ASCII 13 LF ASCII 10 ESC ASCII 27 ASCII 43 they must be escaped by preceding them with an ESC character For example to send the following decimal binary data 00 01 02 13 03 10 04 27 05 43 06 it must be escaped as follows 00 01 02 27 13 03 27 10 04 27 27 05 27 43 06 Further more most instruments will get confused if GPIB termination characters such as CR or LF are appended to binary data Use eos 3 command to disable such behavior See eos command help for more details 5 14 2013 7 Prologix GPIB USB Controller User Manual 8 Commands Prologix GPIB USB controller provides several commands to configure its behavior They are explained in detail in the following sections All commands start with the character sequence Commands must be terminated with CR or LF 8 1 addr The addr command is used to configure or query the GPIB address Meaning of the GPIB address depends on the operating mode of the controller In CONTROLLER mode it refers to the GPIB address of the instrument being controlled In DEVICE mode it is the address of the GPIB peripheral that Prologix GPIB USB controller is emulating An optional secondary address
10. ected maximum value of tread_tmo_ms to 3000 ms April 21 2009 Added status command description Updated addr spoll and trg command descriptions to include secondary address Added section on binaty data transmission Mar 1 2008 Updated trg command description Dec 22 2007 Updated USB command terminator description and read_tmo_ms command description Jul 9 2007 Fixed typo in mode command description Thanks Mike Schulz Jul 7 2007 Added change log Renamed PERIPHERAL mode as DEVICE mode in line with other GPIB literature Jul 5 2007 Initial version 5 14 2013 Prologix GPIB USB Controller User Manual 1 Introduction Prologix GPIB USB controller converts any computer with a USB port into a GPIB Controller or Device In Controller mode Prologix GPIB USB controller can remotely control GPIB enabled instruments such as Oscilloscopes Logic Analyzers and Spectrum Analyzers In Device mode Prologix GPIB USB controller converts the computer into a GPIB peripheral for downloading data and screen plots from the instrument front panel In both modes Prologix GPIB USB controller interprets high level commands received from the host computer and performs the appropriate low level GPIB protocol handshaking 2 Installation Prologix GPIB USB controller can be installed using these easy steps 1 Download drivers for FT245R chip from FTDI website www ftdichip com Connect Prologix G
11. hat require different configuration settings you must change the settings before communicating with each instrument 6 Operating Modes Prologix GPIB USB controller can operate in two modes CONTROLLER and DEVICE You can switch between the two modes using mode command see Commands 6 1 Controller Mode In Controller mode the GPIB USB Controller acts as the Controller In Charge CIC on the GPIB bus When the controller recetves a command over the USB port terminated by the USB terminator CR ASCII 13 or LF ASCH 10 it addresses 5 14 2013 5 Prologix GPIB USB Controller User Manual GPIB instrument at the currently specified address See addr command to listen and passes along the received data When Read After Write feature is enabled See auto command Prologix GPIB USB Controller will addresses the instrument to talk after sending a command in order to read its response All data received from instruments over GPIB is sent to host over USB Read After Write feature simplifies communication with instruments You send commands and read responses without consideration for low level GPIB protocol details When Read After Write feature is not enabled Prologix GPIB USB controller does not automatically address the instrument to talk You must use the read command to read data Controller mode is used to remotely control instruments and to download screen plots by sending plot commands from a host computer
12. ill assert SRQ status Query current serial poll status byte 8 20 trg This command issues Group Execute Trigger GPIB command to devices at the specified addresses Up to 15 addresses maybe specified Addresses must be separated by spaces If no address is specified then Group Execute Trigger command is issued to the currently addressed instrument as set by a previous addr command Refer to the programming manual for a specific instrument s response to Group Execute Trigger command SYNTAX trg lt PAD1 gt lt SAD1 gt lt PAD2 gt SAD2 lt PAD15 gt lt SAD15 gt MODES AVAILABLE CONTROLLER 8 21 ver This command returns the version string of the Prologix GPIB USB controller SYNTAX ver MODES AVAILABLE CONTROLLER DEVICE 8 22 help This command prints a brief summary of all available commands SYNTAX help MODES AVAILABLE CONTROLLER DEVICE 9 Specifications Supported OS Windows 98 2000 XP Vista Mac OS 8 9 X Linux FreeBSD Supported Standards IEEE 488 1 IEEE 488 2 USB 1 1 USB 2 0 GPIB commands not supported PARALLEL POLL PASS CONTROL Power USB bus poweted 5V 100 mA max Supported USB hubs Self powered and Bus powered hubs Indicators TALK LISTEN Dimensions 2 5 in x 2 5 in W x 1 0 in H Weight 3 oz 5 14 2013 15 Prologix GPIB USB Controller User Manual Many thanks to Gerry Glauser for comprehensively reviewing this manual and suggesting several improvements
13. may also be specified Secondary address must be separated from the primary address by a space character Valid secondary address values are 96 to 126 decimal Secondary address value of 96 corresponds to secondary GPIB address of 0 97 corresponds to 1 and so on Specifying secondary address has no effect in DEVICE mode If the command is issued with no parameters the currently configured address primary and secondary if specified is returned SYNTAX addr lt PAD gt lt SAD gt PAD Primary Address is a decimal value between 0 and 30 SAD Secondary Address is a decimal value between 96 and 126 SAD is optional MODES AVAILABLE CONTROLLER DEVICE EXAMPLES addr 5 Set primary address to 5 addr Query current address addr 9 96 Set primary address to 9 and secondary address to 0 NOTE Default GPIB address of many HP GL 2 plotters is 5 8 2 auto Prologix GPIB USB controller can be configured to automatically address instruments to talk after sending them a command in order to read their response The feature called 5 14 2013 8 Prologix GPIB USB Controller User Manual Read After Write saves the user from having to issue read commands repeatedly This command enabled or disabled the Read After Write feature In addition auto command also addresses the instrument at the currently specified address to TALK LISTEN auto 0 addresses the instrument to LISTEN and auto 1 addresses the inst
14. on reset of the controller The process takes about 5 seconds All input recetved over USB during this time are ignored SYNTAX tst MODES AVAILABLE CONTROLLER DEVICE 8 16 savecfg This command enables or disables automatic saving of configuration parameters in EPROM If enabled the following configuration parameters are saved whenever they ate updated mode addr auto eoi eos eot_enable eot_char and read_tmo_ms However frequent updates may eventually wear out the EPROM This command may be used to temporarily disable automatic saving of configuration parameters to reduce EEPROM wear The savecfg setting itself is not saved in EPROM It is always enabled on startup after power up reset SYNTAX savecfg 0 1 MODES AVAILABLE CONTROLLER DEVICE EXAMPLE savecfg 1 Enable saving of configuration parameters in EPROM savecfg 0 Disable saving of configuration parameters in EPROM savecfg Query current setting NOTE 5 14 2013 13 Prologix GPIB USB Controller User Manual savecfg 1 command will immediately save the current values of all configuration parameters in addition to enabling the automatic saving of parameters 8 17 spoll This command performs a serial poll of the instrument at the specified address If no address is specified then this command serial polls the currently addressed instrument as set by a previous addr command This command uses the time out value specified b
15. oped by Ulrich Bangert for developing data acquisition applications Web link to this tool can be found at prologix biz Plotter emulators plotter emulation applications such as 7470 exe PrintCapture and Plottergeist can be used to render screen plots downloaded using Prologix GPIB USB controller Details on how to configure these tools are available at prologix biz 5 Configuration Prologix GPIB USB controller can be configured using any of the following methods Prologix exe Prologix exe is an open source tool developed by John Miles for configuring the controller Web link to the tool can be found at prologix biz Terminal program any terminal emulation program such as HyperTerminal Tera Term Pro or Minicom can be used to configure the controller by manually entering appropriate commands See Commands Using the terminal program open the virtual COM created by the USB driver Serial port parameters such as baud rate data bits stop bits and flow control do not matter and may be set to any value You may want to enable the Local Echo feature in the terminal program to view the commands being entered Please consult the FAQ at prologix biz or the program s user manual for detailed configuration steps for various terminal programs Prologix GPIB USB Controller stores the latest configuration settings in non volatile memory These settings are not address specific If you have multiple instruments on the GPIB bus t
16. rument to TALK If the command is issued without any arguments it returns the current state of the read after write feature SYNTAX auto 0 1 MODES AVAILABLE CONTROLLER NOTE Some instruments generate Query Unterminated or 420 error if they are addressed to talk after sending a command that does not generate a response often called non query commands In effect the instrument is saying I have been asked to talk but I have nothing to say The error is often benign and may be ignored Otherwise use the read command to read the instrument response For example auto 0 Turn off read after write and address instrument to listen SET VOLT 1 0 Non quety command idn Query command read eoi Read until EOI asserted by instrument HP54201A Response from instrument 8 3 clr This command sends the Selected Device Clear SDC message to the currently specified GPIB address Please consult the programming manual for details on how a particular instrument responds to this message SYNTAX clr MODES AVAILABLE CONTROLLER 8 4 eoi This command enables or disables the assertion of the EOI signal with the last character of any command sent over GPIB port Some instruments requite EOI signal to be asserted in order to properly detect the end of a command SYNTAX eoi 0 1 5 14 2013 9 Prologix GPIB USB Controller User Manual MODES AVAILABLE CONTROLLER DEVICE EXAMPLES eoi 1 Enable
17. y the read_tmo_ms command SYNTAX spoll lt PAD gt lt SAD gt PAD Primary Address is a decimal value between 0 and 30 SAD Secondary Address is a decimal value between 96 and 126 SAD is optional MODES AVAILABLE CONTROLLER EXAMPLE spoll 5 Serial poll instrument at primary address 5 spoll 9 96 Serial poll instrument at primary address 9 seconday address 0 spoll Serial poll currently addressed instrument 8 18 srq This command returns the current state of the GPIB SRQ signal The command returns 1 is SRQ signal is asserted low and 0 if the signal is not asserted high SYNTAX srq MODES AVAILABLE CONTROLLER 8 19 status The status command is used to specify the device status byte to be returned when serial polled by a GPIB controller If the RQS bit bit 6 of the status byte is set then the SRQ signal is asserted low After a serial poll SRQ line is de asserted and status byte is set to 0 Status byte is initialized to 0 on power up SRQ is also de asserted and status byte is cleared if DEVICE CLEAR DCL message or SELECTED DEVICE CLEAR SDC message is received from the GPIB controller If the command is issued without any arguments it returns the currently specified status byte SYNTAX status 0 255 5 14 2013 14 Prologix GPIB USB Controller User Manual MODES AVAILABLE DEVICE EXAMPLE status 48 Specify serial poll status byte as 48 Since bit 6 is set this command w
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