Measurement Computing Analyzer488 - Manual (Page 168)

Section 4 Serial Controller
4.74
SPOLL
The Serial Poll command, SPOLL, performs a Serial Poll of bus devices and
responds with number from 0 to 255 representing the decimal equivalent of the eight-
bit device response. Serial Polls are normally performed in response to assertion of
the Service Request (SRQ) bus signal by some bus device. If rsv (DIO7, decimal
value 64) is set, then that device is signaling that it requires service. The meanings of
the other bits are device-specific.
If SPOLL is issued with multiple addresses specified, the Analyzer488 will
perform a serial poll on each device and send the output of each response to the serial
port with the serial output terminator(s) appended.
With no bus address specified, the SPOLL command returns the external SRQ
status. If the SRQ line is asserted, the Analyzer488 will return a "64". If it is not
asserted, the Analyzer488 will return a "0".
This command does not have a query option.
TYPE High Level Controller command
SYNTAX SPOLL [addr[,addr…]]
addr is an IEEE 488 bus device address
RESPONSE 0 or 64 (without addr)
0 to 255 (with addr)
MODE High Level Controller
BUS STATES ATN•UNL, MLA, TAG, SPE, *ATN, data, ATN•SPD, UNT
QUERY None
RESPONSE