Schneider Electric 4000 manual Relay Output Operating Modes, Normal, Latched

63230-300-212	Chapter 5—Input/Output Capabilities
April 2001	Relay Output Operating Modes

RELAY OUTPUT OPERATING MODES

Before we describe the 11 available relay operating modes, it is important to understand the difference between a relay configured for remote (external) control and a relay configured for circuit monitor (internal) control.

Each relay output defaults to external control, but you can choose whether the relay is set to external or internal control:

•Remote (external) control—the relay is controlled either from a PC using SMS or a programmable logic controller using commands via communications.

•Circuit monitor (internal) control—the relay is controlled by the circuit monitor in response to a set-point controlled alarm condition, or as a pulse initiator output. Once you’ve set up a relay for circuit monitor control, you can no longer operate the relay remotely. However, you can temporarily override the relay, using SMS.

NOTE: If any basic setup parameters or I/O setup parameters are modified, all relay outputs will be de-energized.

The 11 relay operating modes are as follows:

•Normal

—Remotely Controlled: Energize the relay by issuing a command from a remote PC or programmable controller. The relay remains energized until a command to de-energize is issued from the remote PC or programmable controller, or until the circuit monitor loses control power. When control power is restored, the relay will be re-energized.

—Circuit Monitor Controlled: When an alarm condition assigned to the relay occurs, the relay is energized. The relay is not de-energized until all alarm conditions assigned to the relay have dropped out, the circuit monitor loses control power, or the alarms are over-ridden using SMS software. If the alarm condition is still true when the circuit monitor regains control power, the relay will be re-energized.

•Latched

—Remotely Controlled: Energize the relay by issuing a command from a remote PC or programmable controller. The relay remains energized until a command to de-energize is issued from a remote PC or programmable controller, or until the circuit monitor loses control power. When control power is restored, the relay will not be re- energized.

—Circuit Monitor Controlled: When an alarm condition assigned to the relay occurs, the relay is energized. The relay remains energized— even after all alarm conditions assigned to the relay have dropped out—until a command to de-energize is issued from a remote PC or programmable controller, until the high priority alarm log is cleared from the display, or until the circuit monitor loses control power. When control power is restored, the relay will not be re-energized if the alarm condition is not TRUE.

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