Call 78: set program port communication rate – Rockwell Automation 1771-DB BASIC MODULE User Manual

Page 266

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Chapter
Call Routines 69–127

13

13 -8

Use CALL 78 to change the program port communication rate from its
default value (1200 bit/s) to one of the following: 300, 600, 1200, 2400,
4800, 9600 or 19200 bit/s. The default communication rate for the
program port is 1200 bit/s if port PRT1 is configured as the program port
or 19200 bit/s if port DH485 is configured as the program port. PUSH the
desired communication rate and CALL 78. The program port remains at
this communication rate unless CALL 73 (page 13 -5) is invoked or one
of these conditions is met:

battery is dead or has been removed

battery-backup capacitor is discharged

if a PROG1 or PROG2 is executed and the EEPROM is removed or not

programmed

power

is

cycled

If this happens the communication rate of ports PRT1 and PRT2 defaults to
1200 bit/s and the DH485 port defaults to 19200 bit/s.

See also the MODE statement (page 11 -20)

Input and Output Arguments

This routine has one input argument and no output arguments. The input
argument is the communication rate you want (300, 600, 1200, 2400, 4800,
9600 or 19200 bit/s).

Syntax

PUSH

desired communication rate

CALL 78

Example

>10 PUSH 4800

>20 CALL 78

This call does nothing. The active LED is supposed to blink while the
BASIC module is in Command mode and remain solid while the BASIC
module is in Run mode.

CALL 78: Set Program Port
Communication Rate

CALL 79: Set the Active
LED Blinking State (No
Operation)

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