Keithley 2400

The Keithley 2400 is a multimeter, there are various Keithleys with different models numbers which do different tasks.

Troubleshooting

Termination character

If a new Keithley won't talk to you then maybe you have one with a different terminating character. There is a configuration macro for setting it set both IEOS and OEOS options are \\r or \\r\\n (the extra slash is because of macro substitutions).