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1. conde aan 12 12 8 16 E A 13 iowa als Maal tata atau teehee 13 13 Diss Specifications 13 7 9 2007 2 Prologix GPIB USB Controller User Manual 7 9 2007 Change Log July 9 2007 Fixed typo in mode command description Thanks Mike Schulz July 7 2007 Added change log Renamed PERIPHERAL mode as DEVICE mode in line with other GPIB literature uly 5 2007 Initial version 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 2 Connect Prologix GPIB USB controller to a computer using USB A B cable 3 Install drivers according to instructions in www ftd2. 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 7 9 2007 12 Prologix GPIB USB Controller User Manual 8 16 trg This command issues a Group Execute Trigger on the GPIB bus Refer to the programming manual for a specific instrument s response to this command SYNTAX trg MODES AVAILABLE CONTROLLER 8 17 ver This command returns the version string of the Prologix GPIB USB controller SYNTAX ver MODES AVAILABLE CONTROLLER DEVICE 8 18 help This command prints a brief summary of all available commands SYNTAX help MODES AVAILABLE CONTROLLER DEVICE 9 Specifications Supported OS Windows 95 98 2000 XP Vista Mac OS 8 9 X Linux FreeBSD Supported Standards IEEE 488 1 USB 1 1 USB 2 0 GPIB commands not supported PARALLEL POLL PASS CONTROL Power USB bus powered 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 2 oz Many thanks to Gerry Glauser for comprehensively reviewing this manual and suggesting several improvements 7 9 2007 13
3. 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 the USB termination character CR ASCII 13 is received or when the internal buffer becomes full LF ASCII 10 CR and ESC ASCII 27 characters must be escaped by preceding them with an ESC character if they are part of USB data All un escaped LF CR and ESC characters in USB data are 1 Internal buffer is 512 bytes but is subject to change in future versions 7 9 2007 6 Prologix GPIB USB Control
4. is set to 1 and EOI 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 EXAMPLES eot_char 42 Append ASCII 42 when EOI is detected eot_chat Query currently configured eot_char 8 8 ifc 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 loc This command enables front panel operation of the currently addressed instrument 7 9 2007 10 Prologix GPIB USB Controller User Manual SYNTAX loc MODES AVAILABLE CONTROLLER 8 10 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 11 read This command can be used to read data from an instrument until FOI is detected or timeout expires or A specified character is read or timeout expires e Timeout expires Timeout is set using read_tmo_ms command and applies to inter character delay i e the delay since the last character was read Time
5. PROLOGIX GPIB USB CONTROLLER USER MANUAL VERSION 4 65 July 9 2007 PROLOGIX BIZ Prologix GPIB USB Controller User Manual Table of Contents gt TRO AU CHO Hai 4 21 4 3 Firmware Upgraden ana cases ace dau teraction arta iota 4 4 4 De 5 a a A e 5 6 1 NORA RAR a a iis 5 6 2 6 Le 8 RE ER ES 7 8 1 7 8 2 E 8 1S A 9 8 4 9 8 5 9 8 6 EO te OLA LS 10 8 7 10 Spc RS OX SPE a Ep N O E 10 8 9 LOE A pS 10 810 11 Headset eee eee hee I EEE 11 8 12 POA ees 12 12 8 14
6. at Prologix GPIB USB controller is emulating If the command is issued with no parameters the currently configured address is returned SYNTAX addr lt address gt where address is a decimal value between 0 and 30 MODES AVAILABLE CONTROLLER DEVICE EXAMPLES addr 5 Set GPIB address to 5 addr Query current GPIB address NOTE Default GPIB address of many HP GL 2 plotters is 5 7 9 2007 7 Prologix GPIB USB Controller User Manual 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 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 or LISTEN auto 0 addresses the instrument to LISTEN and auto 1 addresses the instrument 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 oft
7. en benign and may be ignored Otherwise turn off read after write feature before issuing non query commands Later turn on the feature after issuing query commands to read response For example auto 0 Turn off read after wtite and address instrument to listen SET VOLT 1 0 Non quety command idn Query command auto 1 Turn read after write and address instrument to talk HP54201A Response from instrument Or 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 query command idn Query command read eoi Read until EOI asserted by instrument HP54201A Response from instrument 7 9 2007 8 Prologix GPIB USB Controller User Manual 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 require EOI signal to be asserted in order to properly detect the end of a command SYNTAX eoi1 0 1 MODES AVAILABLE CONTROLLER EXAMPLES eoi 1 Enable EOI assertion with last character eoi 0 Disable EOI assertion eoi Query if EOI ass
8. ertion is enabled or disabled 8 5 eos This command specifies GPIB termination characters When data from host is received 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 0 1 2 3 where 0 CR LF 1 CR 2 LF 3 None MODES AVAILABLE CONTROLLER EXAMPLES eos 0 Append CR LF to instrument commands eos 1 Append CR to instrument commands eos 2 Append LF to instrument commands eos 3 Do not append anything to instrument commands eos Query current EOS state 7 9 2007 9 Prologix GPIB USB Controller User Manual 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 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 8 7 eot_char This command specifies the character to be appended to USB output when eot_enable
9. ichip 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 7 9 2007 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 developed by Ulrich Bangert for developing data acquisition applications Web link to this tool can be found at p
10. ler User Manual discarded As mentioned earlier an un escaped CR acts as the USB terminator The terminating CR is removed and GPIB termination characters specified by command are appended before transmitting data to instruments Any USB input that starts with the 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 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 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 th
11. out is not be confused with the total time for which data is read SYNTAX read eoi lt char gt where lt char gt is a decimal value less than 256 MODES AVAILABLE CONTROLLER EXAMPLES tead Read until timeout read eoi Read until EOI detected or timeout tead 10 Read until LF ASCII 10 is received or timeout 7 9 2007 11 Prologix GPIB USB Controller User Manual 8 12 read_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 500 and 4000 milliseconds SYNTAX tread_tmo_ms lt time gt where lt time gt is decimal value between 500 and 4000 MODES AVAILABLE CONTROLLER 8 13 rst This command performs a power 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 8 14 spoll This command performs serial poll of the instrument at the specified address no address is specified then this command serial polls the currently addressed instrument as set by a previous addr command This command uses the same time out value specified by the read_tmo_ms command SYNTAX spoll lt address gt where address is a decimal value between 0 and 30 MODES AVAILABLE CONTROLLER EXAMPLE spoll 5 Serial poll instrument at GPIB address 5 spoll Serial poll currently addressed instrument 8 15 srq
12. rologix 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 port 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 that require different configuration settings you must change the settings before communicating with each ins
13. trument 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 it addresses the GPIB instrument 7 9 2007 5 Prologix GPIB USB Controller User Manual 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 6 2 Device Mode In Device mode Prologix GPIB USB Controller acts as another peripheral on the GPIB bus In this mode the
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