RS232 Communication with Agilent 34970A

[RTSLVU]

Good to see you got it working. Without seeing your porgram I am going to toss out a little advice for the 34970...

Using these instruments is a two step process.

1. Configure all the measurements you are going to take and build a "scan list"

2. "Scan" the 34970 to take measurements

Here is an example of configuring a 34970 with a 34901 MUX to take one voltage and one current measurement.

The current measurement is actually a voltage across a current shunt using scaling and actual calibrated shunt resistance values.

Here is where I "scan" the 34970 to take measurements

I also attached my Agilent Scan vi, you might find it useful as I modified the Agilent example to give more output types.

[oli.HUB]

Hi !

I am also trying to communicate with the "34970A", But first I need to buy the right cable to connect to the RS232 interface (see the picture below interface number 3).

I was wondering why do you use the cable "USB to Male RS232" because the RS232 interface in the back of the "94970A" is a male so you need a cable "USB to Female RS232" ?  Or maybe do you connect it to the "Alarm Outputs" (interface number 2) ? but then it is not the right interfaces or maybe there is something I don't understand ?

Could you help me ?

Best regards

[RTSLVU]

The 34970A uses a standard "Null Modem" cable 

Preferably one with all of the hand shaking lines in place so you can use higher speeds. 

While a basic cable with Rx, Tx, and ground is all you really need, that type is limited to 9600 baud using Xon/Xoff flow control at best.

A "proper" cable with handshaking can go as fast as 111520 baud using RTS/CTS flow control

[oli.HUB]

Thank you for your reply

Ok, so it is not a straight cable, but a crossed cable, but I don't understand why "AnthonyMN" use a "USB to Male RS232" instead of "USB to Female RS232" because the "RS232" interface is a male interface so I think we need a female connector to plug it into the male connector interface ?

Thank you

[RavensFan]

Where did he ever day he used a USB to Male RS-232?  Though I'm sure that is what he used.

He said he used a FtF null modem cable in message 6 between the USB to RS-232  and the RS-232 of the device.

That is logical.

The instrument has a Male connector.  Doesn't it?

A USB-RS-232 adapter has a male connector.

The null modem cable between them would be Female to Female.

Everything mates!

[oli.HUB]

thank you very much,

I saw it in message 3, but it was indeed outdated, my bad.

The only thing I need to set the serial communication is the drive from labview right? (see picture below)

Or do I need to install an other drive? from Agilent?

[RTSLVU]

NO!

In fact do not install the HP/Agilent/Keysight (or whatever they are called now) drivers, I/O libraries, or "connection expert".

You don't need them and they can conflict with LabVIEW and cause headaches 

[_TestMan_]

Following comment saved the day for me! Thank you so much.

"What about your serial settings? I have found that when using baud rates over 9600 you have to use a proper null modem cable with all the hand shaking lines and use RTS/CTS flow control, not Xon/Xoff"