Describing the parallel port – Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL User Manual

Page 83

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Parallel Port Communications

7–3

Publication 2706-6.1

The Parallel Port has connections for 4 strobe lines and 16 data lines.

KEYBOARD

SW1

SW2

GND

RELAY

L1 L2N

RS-485

250 VAC 3A

12VDC

RS-232

Parallel Port

The 4 strobe lines (MS0–MS3) specify the type of information on
the data lines (D0–D15).

For Message/Variable/Slave run mode, D0–D15 can receive:

message number to trigger

slave address to which message will be sent

variables to be placed in message

16 bit binary

4 digit signed BCD

l digit unsigned BCD

1 character ASCII

For Message List run mode, D0–D15 can receive:

priority msg. number to trigger (interrupts message list)

message number to add to message list

message number to delete from message list

The following shows the relative significance of each data line.

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

MSB (Most Significant Bit)

(Least Significant Bit ) LSB

Describing the Parallel Port

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