HP WaterSkis E1312A, WaterSkis E1412A manual TRIGgerSOURce EXTernal

Triggering the multimeter is a multi-step process that offers triggering flexibility.

1.You must configure the multimeter for the measurement by selecting the function, range, resolution, etc.

2.You must specify the source from which the multimeter will accept the trigger. The multimeter will accept a BUS trigger from the VXIbus, an external trigger from the front panel “Trig” BNC connector or an immediate trigger from the multimeter's internal trigger system.

3.You must make sure that the multimeter is ready to accept a trigger from the specified trigger source (this is called the wait-for-triggerstate) by issuing a READ? or INIT command. A MEASure command always uses an immediate trigger (see the flow chart in Figure 2-1 on page 45).

The Trigger Source The TRIGger:SOURce <source> command configures the multimeter's trigger system to respond to the specified source. The following trigger sources are available:

•BUS: Trigger source is the HP-IB Group Execute Trigger (GET) or the *TRG common command. Within the HP 75000 Series C mainframes, the instrument whose trigger source is “ BUS” and was the last instrument addressed to listen will respond to the HP-IB Group Execute Trigger. The *TRG command differs from GET because it is sent to a specific instrument not a group of instruments. NOTE: B-size controllers do not support the BUS trigger (e.g., HP E1306A command module, HP E1300/E1301A B-size mainframes).

•EXTernal: Trigger source is the multimeter’s external trigger BNC connector (labeled “Trig” on the front panel). A falling (negative-going)

edge of the input signal triggers the multimeter. The external pulse signal must be >1μs, +5V maximum to 0V (TTL levels).

•IMMediate: Internal trigger is always present. If the multimeter is in the wait-for-trigger state (INITiate), TRIGger:SOURce IMMediate sends the trigger. The MEASure and CONFigure commands automatically set the trigger source to IMMediate.

•TTLTrg0 through TTLTrg7: Trigger source is the VXIbus TTL trigger lines. The multimeter is triggered on the falling (negative- going) edge of a TTL input signal. NOTE: B-size controllers do not support VXIbus TTL triggers (e.g., HP E1306A Command Module,

HP E1300/E1301A B-Size Mainframes).

For example, the following program statement selects the external trigger

BNC connector as the trigger source.

TRIGger:SOURce EXTernal

You can change the trigger source only when the multimeter is in the idle state. Attempting to change the trigger source while the multimeter is in the wait-for-trigger state will generate the “Settings conflict” error.

46 HP E1312A/E1412A Multimeter Application Information Chapter 2