How to communicate with instruments using rs232 in lab windows

[CAV]

Hi,

I'm trying to develop an application using Lab Windows CVI for communicate with an Agilent Power Suply E3631A. I've already downloaded the specific driver and I'm using VISA server for configure the driver. I'm connecting the ps through the Serial COM port using a cross over serial cable, but when I try to send a configuration to the power suply it doesn't response.

Does any one know how can I establish communication?

Thanks in advance.
Claudio

[Emilie S.]

Hi Claudio:

Have you tried to establish communication using Measurment and Automation Explorer (MAX)? If not you should definitely try this first. If you go into MAX and open a VISA session to your port under Devices and Interfaces, you can write a command and read the instrument's response from the Basic I/O tab. Did you download the IVI drivers or the Plug and Play drivers? What version of CVI, NI-VISA, and the IVI Compliance Package (if applicable) do you have?

Thank you,

Emilie S.
National Instruments
Applications Engineer

[CAV]

Hello Emilie,

Certainly I used the MAX explorer but when I send a command to the power supply I get a BFFF0015 answer. I'm using the VISA 2.61 and MAX 3.0.2 versions. So I don't know if the cable should have some jumpers between the flow controls signals or perhaps I'm not using the correct version. In the other hand I downloaded the hpe363xa_MS driver for Lab Windows 6.0 for developing an application but when I try to connect to the ps using the hpe363xa_init function I receive a time out, also in this latter driver the init function doesn't have a baud rate parameter to configure the RS232 parameter. Well it seems prety easy to use these drivers but by now I can't find the error if you have some ideas about it I will realy thank you.

Claudio.

[MJF]

This sounds to me like either a miswired cable or a configuration problem with the instrument. Make sure your cable is properly wired, determine if it requires hardware flow control and verify that the instrument is configured to use the interface you want to use. (Many instruments require you to select an interface if there are two or more types present).

Make sure you are really using the COM port you think you are and that it is actually working. You can build a loopback plug to test a serial port, there are a number of places online with instructions to do this. You would then use hyperterminal or something like it to check the port. Finally, verify that the communication parameters (baud rate, etc.) on the PC and the instrument match.