Device won't communicate USB-232/4

[RMROSU]

I am trying to control a laser head (M126N-1064-500 from JDSU) with the basic serial write/read vi labview provides in its examples. The device communicates with RS232, which I have plugged into a 4 port RS232 to USB hub from NI (Part #: USB-232/4). The RS232 is connected into port1 of the hub, and shows up as com3 in NI MAX. The manual for the device is attached, and has information on how to enter commands. I am fairly good with labview, but I have no experience or understanding of how to enter proper commands or what parameters must be met to properly control RS232 devices.

The attachments are as follows:

NPRO_M125-6_User_Manual - User manual for laser head and control box

S3010080 - Back of the laser control box

Untitled - screen shot which shows two attempts. The left side shows the command I entered that when run produced no response. The right side
              shows the error produced by pressing the query button in an NI MAX test.

Can someone please help me (1) determine if I have made an error in the connection or parameter settings that would prevent communication, (2) show me the proper input of a command (examples are in manual but I can't get them to do anything), and (3) offer other advice I may be neglecting.

[BTreece]

I would start off by making sure that you have the latest version of NI-VISA and NI-SERIAL installed.  If you do, then I would start off by trying to conduct a loop-back test.  Also are you using a regular serial cable or a null modem cable?  I would then run a loop back test.  See the following link on how to conduct a loop-back test.  Essentially you are going to jump the read and write pins of the cable and see if you can read/write.  This will help narrow down where the issue is.

Loop Back Test:  http://zone.ni.com/devzone/cda/tut/p/id/3450

Brandon Treece

Applications Engineer

National Instruments

[RMROSU]

I am using Labview 2009, and I am using the latest NI Serial (3.6). I am using the NI USB-232/4 so this sorts out the regular serial vs.. Null modem issue internally, correct? The loop-back test was successful. Where do we go from here?

[RTSLVU]

You need to study section 3.7 very carefully.

Before you even launch LabView you should open Windows Terminal (Hyperterm) and make sure you can comunicate with the instrument.

This will insure your hardware setup is working.

If you can not comunicate through the terminal then you have hardware problems that must be solved first.

Once you get the terminal interface working get used to the commands and their respective outputs.

In Labview you are going to be sending the same "commands" in the form of strings through VISA writes to the com port.

Then you will be receiving strings through VISA reads and parsing the text.