Bird Technologies 4421 - Manual (Page 33)

IEEE-488 GPIB Interface
21
SRQ Mask (Mxx)
Function Selectively masks status bits to prevent unwanted service requests.
Set xx to the sum of the binary values of the desired SRQ trigger bits. For
example, M12 would set the SRQ for both operation complete and underrange
(values 8 and 4). Set xx to “00” to never generate an SRQ.
Remarks If a status bit is masked (bit set to 0), SRQs won’t be generated for that condition.
Table 5-12 SRQ Mask Bits
Status (Ux)
Function Reads a status word and returns the information as a string. Set x to:
z “0” for machine status.
z “1” for error status.
z “2” for revision history.
Remarks After sending the status command, a status word is sent the next time the
unit is addressed to talk. To ensure the correct status is transmitted, the sta-
tus word should be requested as soon as possible after the command is sent.
Machine Status Word (U0) -
The format of the machine status word is shown
in Figure 9. The default values are also shown.
Figure 9 Machine Status Word Format
Binary Value Bit Number Message
1 0 (LSB) Error (IDDC, IDDCO, self-test fail)
2 1 Measurement overrange
4 2 Measurement underrange
8 3 Operation complete
4 Not Used
5 Not Used
6 Can’t mask
7 (MSB) Not Used
Header
Measurement Function
Range
Prefix
Terminator
Trigger
SRQ Mask
EOI Response
TERM – 4 4 2 0 – F C R Y Y P Y Y T T 1 M 0 0 K Y