54
5.4.1 TEMPBUS™ MASTER
Only Point A of a 920
HTC can be configured as a TEMPBUS™ “master.” A TS CONTROL MODE
using either
TS 1 and/or TS 2 should be selected and the EXTERNAL OUTPUT should be set to
TEMPBUS™. This will cause the measured control temperature of Point A to be sent out the
EXTERNAL OUTPUT port.
Notes:
•If a
TEMPBUS™ “master” has its temperature control overridden by an INHIBIT override or a
FORCE ON override signal, it will pass this override signal over the TEMPBUS™ to its “slaves.”
• Load shedding, fail-safe, or auto-cycling conditions are not passed over the
TEMPBUS™ from
a “master” to its “slaves.”
5.4.2 TEMPBUS™ SLAVE
Both Point A and/or Point B of a 920
HTC can be configured as a TEMPBUS™ “slave.” The EXTER-
NAL INPUT
should be set to TEMPBUS™, then the point’s TS CONTROL MODE must be set to a mode
using the
EXTERNAL INPUT. The “slave” controller will perform its own temperature control using
the control temperature of the “master.”
If a
TEMPBUS™ “slave” does not receive a control temperature from a TEMPBUS™ “master” at
least once every 15 seconds, then a
CONTROL TS FAILURE ALARM will occur. This alarm is non-
latching for
TEMPBUS™ “slaves” and will be cleared automatically once a control temperature is
received again. Point B can be a “slave” to Point A of the same controller.
Note: Other features that require the use of the
EXTERNAL INPUT (INHIBIT or OVERRIDE) may not
be used at the same time as the
TEMPBUS “slave” feature.
To Next Page
Loading...
