Maxsys PC4020 - 2.3.6 Locating PC4204 Modules;Correcting Line Loss Problems; 2.3.7 Base Number Chart

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PC4020 Design Notes
2.3.6 Locating PC4204 Modules/Correcting Line Loss Problems
There are three different ways in which line loss problems may be rectified.
Regardless of the method you choose to correct the line loss problem it is absolutely necessary
to maintain a positive number of Power Units on each branch of the system.
1. Wire the system differently. Since line loss depends on distance, the COMBUS may be run in
a different manner to decrease the distance modules are from their power source.
2. Use a thicker gauge wire. By increasing the gauge of wire you will have more Power Units
available for each branch of the COMBUS and may correct the problem.
3. Connect a PC4204 module to power modules with negative power units. It is difficult to make
rules to govern where the PC4204 should be connected but keep in mind the following guide-
lines. Regardless of where you decide to put the PC4204 module the system should be recal-
culated to verify the problem has been corrected.
• No module will operate properly if there are less Power Units available than the module requires.
• If a module has a questionable number of Power Units remaining (any number less than 10) it
would be a good idea to try and locate the PC4204 module so that it could also power these
modules.
• The calculations are only as accurate as the data gathered. If the distances are wrong or
devices requiring power are not included a problem may still exist.
As stated before, correcting line loss problems now, before wiring the job, will allow you to best
determine how to correct the problem. All three options will be available to you and the most
cost-effective method can be used. If the job is already wired the addition of PC4204 modules
will be, most often, your only option.
2.3.7 Base Number Chart
The BASE number for each module is as follows:
PC4108 - 3*
PC4116 - 4*
PC4204 - 0 or (3) - special (See below)
PC4216 - 3*
PC4400 - 3
LCD4500 - 5
The Base Numbers for the modules with the ‘*’ symbol may be increased as devices requiring
power may be connected to these.
For each 10 mA of additional current required by a module for additional devices increase the
Base Number by 1.
The PC4204 module is special. If used to repower the COMBUS it will restore the Power Units to
its original value but is considered to have a Base Number of 0 (it requires no Power Units to
operate).