Dual or Quad Relay Option Boards for Laureate™ Meters, Counters & Timers

Standard Features

Four optional plug-in setpoint controller boards are available to add control and alarm capability to 1/8 DIN Laureate DPMs, counters, timers and remote displays:

The contact relays are rated for 8A at 250 Vac or 24 Vdc and are recommended for high currents. The dual contact relays are mutually isolated Form C relays and can be wired to be normally open (NO) or normally closed ($0) when not energized. The quad contact relays are normally open (NO) Form A relays and share a common isolated ground in pairs.

The solid state relays are rated for 120 mA at 250 Vac or 24 Vdc and are recommended for low currents and frequent switching. They are Form A relays, which are normally open (NO) when not energized. As for the contact relays, the dual solid state relays are mutually isolated, and the quad solid state relays share a common isolated ground in pairs.

Setpoint values and operating modes can be entered via front panel pushbuttons or by computer via the serial interface. Security lockout modes of the front panel pushbuttons can be set to allow operators to view and change setpoint values, view but not changes setpoint values, or not view nor change setpoint values. The Laureate Weight Meter and Batch Controller offer relay control modes beyond those of normal meter or counter operation.

Form C (SPDT) dual contact relays Relays can be connected to be normally open (OC) or normally closed ($0). Relay grounds are mutually isolated.	Form A (SPST) quad contact relays Relays are normally open (NO). Each pair of relays shares an isolated ground.
Form A (SPST) dual solid state relays Relays are normally open (NO). Relay grounds are mutually isolated.	Form A (SPST) quad solid state relays Relays are normally open (NO). Each pair of relays shares an isolated ground.

Setpoint Operating Modes

Normal, Non-Latched Operation
	In this mode, the relay closes when the reading rises above the setpoint and opens when the reading falls below the setpoint. Relay ON/OFF control action is independently programmable for each of the two relays and can be reversed through a setup command.
Latched Operation
	The relay stays actuated until reset externally. This mode can be used to shut down machinery or a process when an operating limit has been exceeded, or to maintain an alarm until acknowledged by an operator when the alarm condition has passed.
Mixed Latched and Non-Latched Operation
	One of the relays can operate in a non-latched mode, for instance to turn off a heater when an operating temperature setpoint is reached. The other relay can operate as a latching fail-safe backup and turn off the entire process when a second, higher setpoint is reached, indicating a malfunction.
Deviation Mode Operation
	A deviation limit (50 in this example) is set up around both sides of the setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and is often used for component testing.
Wide Hysteresis Mode Operation
	In this example, a hysteresis limit of 600 is set below the setpoint. The relay closes when the reading reaches a lower limit (the setpoint less hysteresis) and opens when the reading reaches an upper limit (the setpoint). One application is automatic tank filling. A fill operation is automatically initiated when the tank level has reached a lower level and is terminated when the level has reached an upper level.
Narrow Hysteresis Mode Operation
	Hysteresis can be used to minimize the number of ON/OFF control cycles around a setpoint, thereby increasing the life of motors, relays, etc. A very narrow hysteresis band (such as 5 counts) can also be used to minimize relay chatter around a setpoint due to electrical noise on the signal, or due to signal feedback caused by load switching. The hysteresis limit should exceed the noise amplitude.