Xm Series Of Case Controllers; Xm670; Xm679; Xm678 - Emerson Site Supervisor User Manual

2.2.11 XM Series of Case
Controllers
The XM series is a set of digital case controllers for
low to medium units. The XM series control refrigeration
solenoids and defrost (electric or hot gas), evaporator fans,
lights and have an auxiliary output.

2.2.11.1 XM670

Figure 2-13 - XM670
The XM670 is high level microprocessor based con-
trollers for multiplexed cabinets suitable for applications
on medium or low temperature. It can be inserted in a
LAN of up to 8 different sections which can operate,
depending on the programming, as stand alone controllers
or following the commands coming from the other sec-
tions. The XM670 is provided with 6 relay outputs to con-
trol the solenoid valve, defrost (which can be either
electrical or hot gas) the evaporator fans, the lights, an
auxiliary output and an alarm output. The devices are also
provided with four probe inputs, one for temperature con-
trol, one to control the defrost end temperature of the
evaporator, the third for the display, and the fourth can be
used for application with virtual probe or for inlet/outlet
air temperature measurement. Finally, the XM670 is
equipped with the three digital inputs (free contact) and
are fully configurable. For more information about the
XM670 controller, refer to the controller manual,
P/N 026-1218.

2.2.11.2 XM679

The XM679 is similar to the XM670, but with one
relay output to drive pulsed electronic expansion valves.
The XM679 also contains two probes that are dedicated
for superheat measurement and regulation. Refer to the
XM679 manual (P/N 026-1218) for more information
I/O Board Names and Terminology
about the device.
Figure 2-14 - XM679

2.2.11.3 XM678

The XM678 is similar to the XM670, but with one
stepper valve output to drive an electronic expansion
valve. The XM678 also contains two probes that are dedi-
cated for superheat measurement and regulation. Refer to
the XM678 manual (P/N 026-1219) for more information
about the device.
Figure 2-15 - XM678
RS485 I/O Network Boards and Peripherals
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