RS232 to GPIB convertor

[Grey]

Hi,

I'm using an ATE in which i'm controlling many measurement devices thorough GPIB interface only.

One of the instrument - Voltech- PM300 Power Analyzer gone bad and i have a standby Power Analyzer.

Unfortunately the standby instrument doesn't have the GPIB interface but it consists of RS232 interface.

If i use RS232 to GPIB convertor, does this solve my problem? Any settings need to be done in program?

How i can assign the GPIB Device No? does this reflect in MAX?

I never used this RS232-GPIB Convertor, but i want to make sure everything is fine before buying.

please advice.

thanks.

[crelf]

So let me get this straight: you've got a bunch of GPIB instruments in your system, one of them goes down and the replacement is RS-232 only. Is that right? If so, why not connect RS-232 directly to your PC (if you have a port)? Or get a USB<->RS-232 adapter? Either way, if you're using VISA, it's just a matter to replace the GPIB resource name with the new one in MAX.

[Grey]

Dear Crelf,

I did the same way you explained.

I'm using USB-rs232 Convertor.

I changed the visa resource name in the code but it not worked. i do not know why so...

i re-write new codes for serial communication part and updated my existing code.

why i asked serial to GPIB convertor is, in that case i no need to change anything except making sure the device number in MAX is matching with softwar VISA resource name..

thanks for the reply.

[Rolf Kalbermatter]

Dear Crelf,

I did the same way you explained.

I'm using USB-rs232 Convertor.

I changed the visa resource name in the code but it not worked. i do not know why so...

i re-write new codes for serial communication part and updated my existing code.

why i asked serial to GPIB convertor is, in that case i no need to change anything except making sure the device number in MAX is matching with softwar VISA resource name..

thanks for the reply.

You might have to make sure the instrument driver properly terminates all send commands with CR, LF or CR/LF depending on your instrument for it to work over RS-232. On IEEE-488.2 there is a specific handshake line to indicate an end of message, and most instruments support that by default (unless they are from before 1980 or so). On RS-232 there is no such way to indicated the end of a command, so this needs to be done with a specific character sequence, which is device dependent. Almost all devices offering GPIB and RS-232 options, will accept the additional character sequence without any trouble on GPIB messages too.

Also make sure you initialize the VISA sessions to terminate all reads on the last character of your device specific termination character sequence. That can be done through properties in your initialize VI. Usually instrument drivers that are properly programmed for multi-interface operation, do read the "interface type" property and do a few additional configuration settings in case of serial interface, such as the "terminate on read" setting, but also baudrate, bitlength, stopbits and partity which are important for RS-232.