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5.2 Relay output
PMAC735A-/B- provides two relay operation modes. They are remote control and local control.
The action of relay is different in these two modes. So, users should distinguish the relay is in
remote control mode or in local control mode at first.
The default control mode of this product is remote control. Users can change the mode through
communication.
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Remote control (external) - The relay is controlled by a PC or PLC by using commands
through communication.
◆
Local control (internal) - The relay is controlled by one of the electrical parameters inside
the meter, which serves as the response to the control alarm conditions of a set point.
Once the relay has been in the remote control mode, even though the local control conditions
have been set, the relay will not operate. The relay mode must be set at local control mode.
The two relay operation modes are as follows:
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Normal:
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Remote control: By receiving a command from a PC or PLC, the relay closes. The relay’s
status will be kept until the PC or PLC gives a release command or the meter is
de-energized.
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Local control: When an alarm signal activating the relay is generated, the relay operates.
The relay will not be released until all the alarm conditions activating the relay disappear or
the meter is de-energized. If the power supply for the meter is resumed and the alarm
conditions still exist, the relay will operate again.