Service Requests - Fluke 45 User Manual

A measurement is triggered while the input is greater than +3 V. A method for using
DTR (pin 4) and an external switch to trigger a measurement is shown in Figure 5-2.
Send the IEEE-488 GET interface message (IEEE-488 Operations).
Type
1
2
3
4
5
Table 5-4. RS-232 and IEEE-488 Reading Transfer Rates
RATE
Slow
Medium
Fast
Figure 5-2. External Trigger Using Receive Pin (RX) of RS-232 Interface
Service Requests (IEEE-488 Only and Status Registers
Service requests let a meter on the IEEE-488 bus get the attention of the host. Service
requests are sent over the service request (SRQ) bus line.
If the meter is in the remote state without front panel lockout (i.e., REMS), a
service request can be sent from the front panel by pressing
If more than one instrument on the bus is capable of sending service requests, the host can
determine which instrument made the request by taking a "serial poll." Each instrument on
Table 5-3. Trigger Type
Trigger
Internal
External
External
External
External
Readings per Second
Internal Trigger Operation
(Trigger 1)
2.5
4.5
4.5
DTR (PIN 4)
RX (PIN 2)
Note
Operating the Meter Using the Computer Interface
Service Requests (IEEE-488 Only and Status Registers
Rear Trigger
Disabled
Disabled
Disabled
Enabled
Enabled
Internal Trigger Operation
TRIGGER TO P
Settling Delay
—
Off
On
Off
On
(Trigger 4)
1.5
2.4
3.8
aam20f.eps
.
5
5-13