MA1044 MAQ20-RTD31/-RTD41 Hardware User Manual
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11.0 Expanding a System
The MAQ20-COMx Communications Module periodically scans the system and will detect if a
MAQ20 I/O module has been added. When this happens the next available sequential Registration
Number is assigned to the module.
Standard system expansion involves a simple three step process:
STANDARD EXPANSION PROCESS
1.) Turn system power on and observe communications activity on the I/O modules.
2.) Add a single MAQ20 I/O module in any local or remote backbone position. Observe that the
green Power LED is on and communications activity is seen on the TX and RX LEDs. Allow 1
second for registration. This module has now been assigned the next available sequential
Registration Number.
Label and connect input/output wiring to the I/O module and if desired record physical position in
the system.
3.) Repeat Step 2 for all remaining MAQ20 I/O modules to be added to the system. Subsequent
modules installed are assigned the next sequential Registration Number.
ALTERNATE EXPANSION PROCESS
1.) With system power off, install all additional MAQ20 I/O modules in any vacant local or remote
backbone positions. Label and connect field wiring to the I/O module and if desired record
physical position in the system. Do not apply power.
2.) Apply system power and observe that each module has the green Power LED on and
communications activity is seen on the TX and RX LEDs. Registration is complete when module
TX and RX LEDs all have a repeating blink pattern. Added modules have now been assigned the
next available sequential Registration Numbers, but in a random sequence not associated with
the physical position on the backbone. Modules previously installed and registered in the system
retain their assigned Registration Numbers.
NOTES:
Once the registration process is complete Registration Numbers are permanent as long as I/O modules are not
removed from or added to a system. When system power is cycled or the system is reset, I/O module
Registration Numbers will always remain the same. If I/O modules are removed while the system is powered,
they will be unregistered and the slots or registration numbers become available to register modules once
inserted. If I/O modules are removed while the system is powered and then the power is cycled, the remaining
modules will remain registered with their assigned Registration Numbers. Tools within MAQ20-940 ReDAQ
Shape Software for MAQ20 allow the user to reassign and save Registration Numbers. Refer to the
MAQ20 I/O
Module Registration
section for further details.
Module Detect: A write to the Module Detect register at I/O module register address 98 plus the module offset
based on Registration Number will blink the STAT LED on the top angled surface of the module at a 5Hz rate
for 5 seconds so the module location in a system can be visually identified.
