Specifications

Glossary
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output polarity
An output channel’s polarity determines when the output module turns its field
actuator on and when it turns the actuator off. If the polarity is normal, an output
channel turns its actuator on when the master controller sends it a 1. If the polarity
is reverse, an output channel turns its actuator on when the master controller sends
it a 0.
output response time
The time it takes for an output module to take an output signal from the Island bus
and send it to its field actuator.
P
parameterize
To supply the required value for an attribute of a device at run-time.
PDM
power distribution module. A module that distributes either AC or DC field power to
a cluster of I/O modules directly to its right on the Island bus. A PDM delivers field
power to the input modules and the output modules. It is important that all the I/O
clustered directly to the right of a PDM be in the same voltage group—either
24 VDC, 115 VAC, or 230 VAC.
PDO
process data object. In CAN-based networks, PDOs are transmitted as unconfirmed
broadcast messages or sent from a producer device to a consumer device. The
transmit PDO from the producer device has a specific identifier that corresponds to
the receive PDO of the consumer devices.
PE
protective earth. A return line across the bus for fault currents generated at a sensor
or actuator device in the control system.
peer-to-peer communications
In peer-to-peer communications, there is no master/slave or client/server
relationship. Messages are exchanged between entities of comparable or
equivalent levels of functionality, without having to go through a third party (like a
master device).