Agilent Technologies L4400 manual Scanning with External Instruments

Operating and Programming 3

•The Monitor mode is automatically enabled on all channels that are part of the active scan list. If you define the scan list after monitoring has already been enabled, any channels that are not part of the active scan list will be ignored during the monitor operation (no error is generated).

•Mx+B scaling and alarm limits are applied to the selected channel during a Monitor and all alarm data is stored in the alarm queue (which will be cleared if power fails).

•You can monitor a digital input channel or totalizer channel even if the channel is not part of the scan list. The count on a totalizer channel is not reset when it is being monitored (the Monitor ignores the totalizer reset mode).

The following command is used to enable the channel Monitor mode (default):

ROUTe:MONitor:MODE CHAN

The following program segment selects the channel to be monitored (single channel only) and enables the Monitor function.

ROUTE:MON:CHAN (@1003)

ROUTE:MON:CHAN:ENABLE ON,(@1003)

ROUTE:MON:STATE ON

To read the monitor data from the selected channel, send the following command. Each reading is returned with measurement units, time stamp, channel number, and alarm status information (see “Reading Format" on page 79).

ROUTe:MONitor:DATA?

Scanning with External Instruments

Usage:

•L4421A 40- Channel Armature Multiplexer

A common application of the the L4421A is to scan the multiplexer channels using a “separate” instrument such as a DMM. The DMM can be connected to the multiplexer’s COM terminals on its terminal block (Figure 3- 13), or it can be connected and synchronized using the multiplexer’s “Analog Busses” and “Ext Trig” ports.

L4400 User’s Guide 81