QTech Data Systems Multi Point Controller (MPC) System - Manual (Page 4)

QTech Multi Point Controller for WP2P - Quick Start Guide – v1 – August 2012 4
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Workbench User Interface
This is where the configuration of the Multi Point Controller takes place. There is no
configuration of the WP2P modules.
Overview – Number of WP2P Slave Modules.
This is where the number of WP2P modules in the Multi Point Controller system is
defined. There can be a maximum of eight modules.
Ideally, the amount of modules is defined when the system is purchased so QTech
can preconfigure them. However, additional modules can be added at a later date.
Please note that all of the modules in a Multi Point Controller are specifically
configured at QTech, normal WP2P modules cannot be added to a Multi Point
Controller system.
Each WP2P module is labelled with both a unique serial number and a 6 digit radio
code that is the same for all modules in a system.
The last number of the radio code shows which WP2P slave module it is, in this
example Module 1.
Note – All WP2P modules for a Multi Point Controller system are
specifically configured at QTech. Normal WP2P modules cannot be added.
Overview – Communications.
Poll Period
All of the configured WP2P modules are polled in sequence to synchronise their I/O.
The Poll Period specifies the time duration between the start of each polling
sequence. The poll period is specified in milliseconds. This setting is important as it
defines the worst-case latency between activating a given digital input and the
corresponding digital output activating. With a shorter Poll Period the I/O is scanned
more frequently, but there is a downside in that there will be more radio traffic.
Note - The specified Poll Period value must satisfy the following
relationship: poll period > number of slaves x number of reties x retry timeout
Retry Timeout
When the Controller polls a given WP2P it waits, listening for a reply before
communicating with the next WP2P module in the sequence. The Retry Timeout
specifies how long the Controller will wait for the reply. Depending on the application
and quantity of modules, 200ms (0.2 seconds) should be a good starting point.
Number of Retries