Example

Status Reporting

Conducting a Parallel Poll

The value of Mask (any numeric expression can be specified) is first rounded and then used to configure the device’s parallel response. The least significant 3 bits (bits 0 through 2) of the expression are used to determine which data line the device is to respond on (place its status on). Bit 3 specifies the "true" state of the parallel poll response bit of the device. A value of 0 implies that the device’s response is 0 when its status bit message is true.

The following statement configures the device at address 07 on the interface select code 7 to respond by placing a 0 on bit 4 when its status response is "true."

PPOLL CONFIGURE 707;4

Example

Conducting a Parallel Poll

The PPOLL (Parallel Poll) function returns a single byte containing up to 8 status bit messages for all devices on the bus capable of responding to the poll. Each bit returned by the function corresponds to the status bit of the device(s) configured to respond to the parallel poll (one or more devices can respond on a single line). The PPOLL function can only be executed by the controller. It is initiated by the simultaneous assertion of ATN and EOI.

Response = PPOLL(7)

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HP Sander 16500C manual Conducting a Parallel Poll