Chapter 3
28
Mini-Convectron Module with RS-485
Instruction Manual - 275545
3.3
Digital Communications
Syntax/Address Overview
A command from the host must include a start character, address, data, and
terminator:
(start character)(address)(data)(terminator)
• The start character is "#"
• The address is two ASCII digits representing the Hex address of the
module.
Example: 0F is address 15
• The data field is explained in the command descriptions. All command
examples are shown with an address of 01. If the address is changed, both
the command and response will have the new address instead of 01. All
alpha characters can be upper or lower case. The response is in upper
case.
• The terminator character is “control” M or Hex 0D for a carriage return
“CR”, and “_” space signified below by:
__ = space
CR = carriage return.
All data fields responses will contain 13 characters, uppercase alpha
characters. The commands are of various character lengths
A response of ?01_SYNTX_ER CR is caused by an incorrect character string
sent from the host, or when the syntax is not recognized by the module.
RS-485 Address Switch
Settings
The address switch sets the base module address. The address switch ranges
from 0 to 15 (00 Hex — 0F Hex). There is an address offset, set by the “SA”
command that can set additional address offsets through the RS-485
interface.
Baud Rate, Stop Bit and
Parity
The baud rate, stop bit setting and parity setting are all changed through the
RS-485 interface. The new settings take effect when the power is cycled, or
when an “RST” command is sent over the interface. The Baud rate, stop bit,
and parity can be set to the factory default values using the “FAC” RS-485
command.
Table 3-2
Default Settings
Function
Default setting
Baud rate
19.2 Kbaud
Data format
ASCII 8 databits, 1 stopbit, no parity
Address
01
