Dn (Display Commands); Gn (Get Commands); Tn (Trigger Mode Commands); Wn (Terminator Commands) - Fluke 8845A Manual

8845A/8846A
Programmers Manual

Dn (Display Commands)

An 8842A D1 command blanks the numeric field in the 8842A display. A D1 command
in 8842A emulation mode will blank the ENTIRE 8845A/8846A display.

Gn (Get Commands)

The G2 Get Calibration Input Prompt command in 8842A emulation mode is not
supported. Entering this command will generate an Error 51. The G3 (Get User-Defined
Message) command would normally return a user defined message set using the P3
command; however the 8842A emulation doesn't support the P3 command. Entering a
G3 command will cause a response similar to the following:
FL8842A.1-8-2008

Tn (Trigger Mode Commands)

The 8842A differentiates between front and rear trigger inputs. The 8845A/8846A treats
the front and rear trigger inputs as the same. The 8842A commands T1 and T2 are treated
as the same command in 8842A emulation mode (external trigger with auto trigger delay
enabled). Furthermore, the 8842A commands T3 and T4 are treated as the same
command in 8842A emulation mode (external trigger with auto trigger delay disabled).
An external trigger (T1 – T4) will not trigger the unit from the front panel until you take
the Meter out of remote operation by pressing the front-panel's LOCAL button. The front
panel is locked out during remote operation. After putting the Meter into local operation,
press the front panel TRIG button to trigger a reading. The 8845A/8846A can be
externally triggered in remote or local operation through the rear panel external trigger
jack.

Wn (Terminator Commands)

The 8845A/8846A does not support W6 (Enable EOI Only) or W7 (Disable All Output
Terminators) in 8842A emulation. When sent to the Meter, W6 and W7 will be ignored.

Numeric Entry Command

Because the P2 and P3 (calibration) commands aren't supported, entering numerical
exponent values are limited to the P0 (Put Instrument Configuration) and P1 (Put SRQ
Mask) commands. P0 is limited to numbers between +1000 and +6824 and the P1
command is limited to numbers between 0 and +63.

Talk-Only Mode

The 8845A/8846A does not support Talk-Only mode. However, it does support TALK
mode which means the controller can address the unit to talk and read measurements
from the IEEE-488 bus at any time (provided there is a measurement there to be read).

Ranging in 8842A Emulation Mode

The 8842A has range boundaries in orders of 2 (2, 20, and 200). Furthermore, the
maximum current input is 2 A and the maximum resistance measurement is 20 MΩ. To
simulate 8842A ranging using the 884XA design, the 8845A/8846A selects the "higher"
range (e.g. if the user selects the 2V 8842A range, the 8845A/8846A selects the 10V
range in 8842A emulation mode). Table 41 lists the range mapping of the 8845A or
8846A while in the 8842A emulation mode.
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