Measurement Computing Analyzer488 - Manual (Page 146)

Section 4 Serial Controller
4.52
PPOLL CONFIG
The Parallel Poll Configure command, PPOLL CONFIG, configures the
Parallel Poll response of a specified bus device. Not all devices support Parallel
Polling and, among those that do, not all support software control of their Parallel Poll
response. Some devices are configured by internal switches.
The Parallel Poll response is set by response, a four-bit binary number (S
P2 P1 P0 ). The most significant bit of response is the Sense (S) bit. The Sense
bit is used to determine when the device will assert its Parallel Poll response. Each bus
device has an internal individual status (ist). The Parallel Poll response will be
asserted when this ist equals the Sense bit value. ist is normally a logic "1" when the
device requires attention, so the S bit should normally also be a logic "1". If the S bit
is "0" then the device will assert its Parallel Poll response when its ist is a logic "0",
i.e. it does not require attention. However, the meaning of ist can vary between
devices, so refer to your IEEE 488 bus device documentation.
The remaining 3 least significant bits of response, P2, P1, and P0, specify
which DIO bus data line will be asserted by the device in response to a Parallel Poll.
These bits form a binary number with a value from 0 through 7, specifying data lines
DIO1 through DIO8, respectively.
TYPE High Level Controller command
SYNTAX PPOLL CONFIG addr;response
addr is an IEEE 488 bus address.
response is the decimal equivalent of the four binary bits S, P2,
P1 , and P0.
RESPONSE None
MODE High Level Controller