Measurement Computing Digital488 - Manual (Page 51)

Section 3 Command Descriptions
3.21
Port Pn
The Port command determines which port is selected for data input/output. In
the default mode (P0), all ports are selected. The P1 thru P5 commands select a
specific eight bit port.
It is recommend that the Bus Output command be used with the PO mode to
determine which ports will be output when the Digital488 is addressed to talk.
Data in modes P1 throuth P5 will be input or output in groups of eight bits.
P0 All five ports are selected
P1 Port 1 is selected
P2 Port 2 is selected
P3 Port 3 is selected
P4 Port 4 is selected
P5 Port 5 is selected
Example:
CLEAR 718 reset the Digital488
OUTPUT 718;"P4X" select port 4