Rs-485 Operation - Equinox Systems PPM3 MK2 User Manual

3.5 RS-485 Operation

It is possible to network up to 16 x PPM3 programmers on an RS-485 network and control them from
a single 'Supervisor PC' running a single session of the Equinox EQTools or ISP-PRO software. This
scenario requires that each PPM3 programmer is set to 'RS-485' operation and that a unique 'Node
Address' is set for each programmer. An RS-232 to RS-485 converter is also required to convert the
RS-232 signal from the PC COM port to an optically isolated RS-485 signal suitable for interfacing
with the PPM3's on the network.
The typical setup is shown in the figure below.
Fig. 3.5 Setup for RS-485 Communications (Multi channel)
For RS-485 operation:
•
Place the PPM3 programmers side-by-side on a flat surface with the rear panels all facing in
the same direction as detailed in fig. 3.5
•
For each PPM3 programmer, set the RS-232 / RS-485 DIP Switch (5) to the RS-485 position
•
For each PPM3 programmer set the required Node Address in the range 0 – 15.
(Each programmer must have unique address. It is customary to start have the first
programmer set to address 0, the next programmer in the chain at address 1 and so on. See
section 3.3 for further details.)
•
Plug the 9-way RS-232 cable into the port on the RS-232 to RS-485 converter and connect
the other end of the cable to a spare PC COM port.
•
Plug an RS-485 network cable from one of the RS-485 outputs on the RS-485 converter to the
'RS-485 Input' connector (left-hand connector) on the rear panel of the first PPM3 Module.
•
Plug another RS-485 network cable from the 'RS-485 Output' connector (right-hand
connector) on the rear panel of the first PPM3 to the next PPM3 in the chain.
•
A return RS-485 cable from the last PPM3 in the chain to the RS-485 converter is NOT
required.
•
Power up the PC.
•
Plug in and switch on the power supply adaptor supplied with the RS-232/RS-485 convertor
into a spare mains socket.
•
Power up all PPM3 Programmers.
•
Launch the ISP-PRO software on the PC and set up the required number of PPM's within the
software.
•
Test that all PPM3's are communicating with the PC at their correct 'Node Address'. (The
Node Address may be changed while the programmer is powered up).
PPM3 MKII Programmer - User Guide - V1.04 - 10
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