Measurement Computing Digital HS - Manual (Page 17)

SRQ On External Status Bit 2 (SB2) Selection
2.2.2.3 Digital Output Port Setup
Several features are available for the output port. These features are selected by
internal switch S3, labeled OUTPUT SETUP. The factory defaults for these feature
selections are shown in the following.
The features include:
SRQ On Output Port Empty (Serial Poll Feature)
ist Enable on Output Port Empty (Parallel Poll Feature)
Polarity Selection for Output Data, oEND, oTrigger, oClear,
oDAV and oBusy Lines
The digital output port contains 16 bits of TTL level outputs, one END line (oEND),
two handshake lines (oDAV and oBusy), four control lines (/oRESET, /OE, oClear
and oTrigger) and logic supply lines (+5V and ground).
S3
SRQ EN EMPTY ist EN EMPTY oDAV POL oBUSY POL oEND POL oDATA POL TRIGGER POL CLR POL
OPEN
8 7 6 5 4 3 2 1
Output Port Feature Selection Switch
Default Settings
2.2.2.3.1 S3-1 SRQ EN EMPTY: Service Request Enable