Instruction manual

5554
Digital
C o m m u n i c a t i o n s
Figure 20. General Communications Message Format
For proper digital communication with the controller(s), make the
following checks:
• Baud rate of the controller(s) must match that of the computer
or PLC device.
• Controller communication cable is connected to the correct
serial port on your computer or PLC.
• Data TX and RX lines are going to the proper connector pins. If
you are using RS422 line, short the RX+ and TX+ together
(“A” signal) and the RX- and TX- together (“B” signal).
See wiring diagram, page 9.
Caution:
Modifying parameter
#19 (Baud Rate) by
host may cause loss of
data link.
#[controller id] [command] [parameter number]<new value><units> [CR]
Start of
message
End of
message
Up to TWO
Numeric
Characters
00 to 99
Up to TWO
Numeric
Characters
00 to 99
Up to SIX
Characters
ONE Leading
Sign
‘-’,‘+’or
Space and
FOUR
Numeric
Characters
with decimal
for decimal
parameters
OPTIONAL
OPTIONAL
ONE
Character
Upper case
or Lower case
R Read
M Modify
E Enter
ONE
Character
F Deg F
C Deg C
U PROCESS
SENSOR
None for default
Temperature units
of NON-THERMAL
parameters
N ON
(Select)
F OFF
(Deselect)
? STATUS
0 Standby
1 Autotune
2 Manual
3 Ramp
9 Version
(Status Only)
SPECIAL
COMMANDS
Example: For Standby “On”, type #01N0[CR].
Digital
C o m m u n i c a t i o n s
Interface Examples
This section describes the protocol for communication
between the controller and either a video display terminal or
computer ( referred to below as “the host”). Message strings
may be of two types — commands to controller or responses
from controller.
General Comments
One host and multiple controllers may be interconnected on a
single bus. The host may send commands to any controller
and may receive responses from any controller. Each con-
troller on the bus is assigned an identification code between
00 and 99. No two controllers on a given bus may have the
same identification code. Controllers are not capable of com-
municating with other controllers.
Every valid message begins with a pound-sign (#) character.
Every valid message ends with a carriage-return (<CR>)
character.
A valid message is composed of: Start Character, Controller
ID Code, Command, Parameter, Data, Carriage-Return.
Every response begins with a line-feed (<LF>) character and
ends with a carriage-return, line-feed pair (<CRLF>).