Serial Communications Ports; Overview - Equinox Systems PPM3 MK2 User Manual

3.0 Serial Communications Ports

3.1 Overview

The PPM3 Programming Module can be controlled from any external device which supports either the
RS-232 or RS-485 hardware communications protocols. The Module features an RS-232 port which
can connect to a COM port of any suitable Control System such as a PC running the Equinox
EQTools software. This mode of operation is restricted to a single programmer channel.
In many medium to high volume production applications there is a requirement to run more than one
PPM3 programmer from the same PC COM port. This can be achieved by daisy-chaining up to 16
modules (using the RS-485 In/Out ports on each programmer) on an RS-485 bus and using an RS-
485 converter to convert the PC RS-232 COM port to the required RS-485 levels. The Equinox ISP-
PRO Software Suite is required to run the programmers in this mode.
The table below details the applications of both the RS-232 and RS-485 communications modes.
Fig. 3.1 PPM3 – Comparison of RS-232 / RS-485 Serial Communication Interfaces
Mode Maximum
Programming
channels
RS-232 1
RS-485 16
PPM3 MKII Programmer - User Guide - V1.04 - 10
Programmer Serial
Node port
Address
0
RS-232
(can be
port (3)
altered)
0-15
RS-485
port
(4 & 5)
th
May 2008
Description
•
Single Channel RS-232 Operation
•
Set 'Communications Mode
Switch' to 'RS-232'
•
Programmer connects to PC COM
port or other RS-232 Control
System via RS-232 cable.
•
Programmer Communications
Node Address is set to '0'
•
This is the factory default setting.
•
Multi-channel RS-485 operation
•
Set 'Communications Mode
Switch' to 'RS-485'
•
Allows up to 16 x PPM3 Modules
to be daisychained from one PC
COM port.
•
Requires an external RS-485
Converter
•
If more than one module is to be
connected to the same PC, then
the Equinox ISP-PRO Software
Suite is also required.
•
Programmer Communications
Node Address on each module
must be set to a unique address
between 0 and 15.
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