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Ibppc, Table 3-5. values for p2-p0, Ibppc -32 – Measurement Computing GPIB-488 User Manual

Page 45

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Chapter 3

GPIB 488.1 Library Reference

Programming Reference Manual

3-32

GPIB-488

IBPPC

Enables/Disables parallel polling of the specified device.

Syntax

C

ibppc (int boarddev, int command)

Parameters

boarddev

is an integer containing the board or device handle. This value is obtained by

calling the

ibfind

routine.

command

is a valid parallel poll enable/disable message or 0. If command represents a PPE

message, then the device will use that message to respond to a parallel poll. Valid PPE
messages range from 60 to 6F hex. The PPE specifies the GPIB data line (DIO1 through
DIO8) on which the device is to respond and whether that line is to be asserted or unasserted.

The PPE byte is of the format:

Where

SENSE

indicates the condition under which the data line is to be asserted. The device

compares the value of the sense bit to its IST (individual status) bit and responds
appropriately. For example, if SENSE = 1, the device will drive the line TRUE if its IST = 1
or FALSE if IST = 0.

P2

P0

specify which GPIB data line should be used to respond to a parallel poll, as shown in

Table 3-5.

7

6

5

4

3

2

1

0

0

1

1

0

SENSE

P2

P1

P0

Table 3-5. Values for P2–P0

P2

P1

P0

GPIB Data Line

1

1

1

DIO8

1

1

0

DIO7

1

0

1

DIO6

1

0

0

DIO5

0

1

1

DIO4