Sunday, February 14, 2010

Check DirectX Version

To check DirectX version run "dxdiag" from Start/Run.


Monday, February 8, 2010

Agilent U1251A/U1252A/U1253A DMMs - Connect To Computer

Similarly to Fluke 189/289 DMMs
Agilent U1251A/U1252A/U1253A DMMs can be connected to a computer too. The Agilent DMMs need IR-USB U1173A cable for that.

Check U1251A/U1252A User’s and Service Guide for details. The same as with Fluke DMMs connection to the Agilent DMMs is represented as a COM port on system level:

Agilent provides its own software, Agilent GUI Datalogger, for measurement automation which is very convenient. However it is not a big deal to write a custom code for the Agilent DMMs if there is a necessity, for instance, to control some different devices from one program. Here is a screen shot of Agilent GUI Datalogger with the list of commands and the connection parameters:

Identification command "*IDN?" allows to find automatically the COM port assigned to the DMM, command "READ?" returns a measured value:


Monday, February 1, 2010

Fluke 189/289 DMM - Connect To Computer

Some of multimeters as Fluke 189 or 289, for instance, can be connected to a computer. That allows easily to setup communication with such a device and automate measurements. Fluke 189/289 needs Fluke IR189USB cable for that. While it is USB port physical connection it's represented as a serial COM port on operating system level.

Has to be mentioned that Fluke provides its own software to communicate with the DMMs: FlukeView Forms. Nevertheless due to simplicity of the interface connection can be easily controlled from available in Windows HyperTerminal, for example, or from a simple custom program or script. The detailed list of commands and parameters of the communication protocol can be found here.

To set it up:
  1. Install drivers for corresponding operating system. FTDI USB chip is used in the cable, a corresponding driver is available for downloading from here.

  2. Connect a Fluke 189/289 to a computer USB port.

  3. Check what port number was assigned for the Fluke multimeter: Start/MyComputer/Properties/Hardware/Device Manager/Ports

  4. Open a serial terminal program, for example, Hyperterminal in Windows, choose the port and setup parameters of the connection as 9600 baud, 8 bits, no parity, 1 stop bit.

  5. Send commands and read responses:

Reading a currently measured value is done by sending out Query Measurement "QM" command. Identification "ID" command can be used to find automatically that port which Fluke DMM was assigned to.