Siemens bt300 Operator's Manual page 119

Monitoring (M5.8.3.2)
The following monitoring values are available for the N2 fieldbus protocol:
Menu
M5.8.3.2.1 Fieldbus Protocol Status
M5.8.3.2.2 Communication Status
M5.8.3.2.3 Invalid Data
M5.8.3.2.4 Invalid Commands
M5.8.3.2.5 Command NACK
M5.8.3.2.6 Control Word
M5.8.3.2.7 Status Word
N2 Point Map
Analog Inputs (AI)
All analog inputs (AI) points have the following features:
● Support Change of State (COS) reporting based on high and low warning limits.
● Support Change of State (COS) reporting based on high and low alarm limits.
● Support Change of State (COS) reporting based on override status.
● Always considered reliable and never out of range.
● Writing alarm and warning limit values beyond the range that can be held by the drive's internal variable will
result in having the limit replaced by the Invalid Float value even though the message is acknowledged. The
net results will be the inactivation of the alarm or warning (the same as if the original out of range value was
used).
● Overriding is supported from the standpoint that the "Override Active" bit will be set and the value reported to
the N2 network will be the overridden value. However, the value in the drive remains unchanged. Therefore,
the N2 system should be set up to prevent overriding AI point or have an alarm condition activated when an AI
point is overridden.
● Overriding an AI point with a value beyond the limit allowed by the drive's internal variable will result in an
Invalid Data error and the override status and value will remain unchanged.
Siemens Industry, Inc.
Building Technologies
Table 89: N2 Fieldbus Protocol Monitoring.
Parameter ID
2399
2400
2041
2402
2403
2402
2405
Siemens BT300 HVAC Drive
Chapter 4 - Parameters and Menu Structure
Min Max
Initializing Faulted Displays the current protocol status as follows:
0 = Initializing
1 = Stopped
2 = Operational
3 = Faulted
0.0 99.999 Displays the number of bad frames and good
messages in the following format:
xx.yyy where xx indicates the bad frames and yyy
indicates the good messages.
Active if one or more of the fields in a fieldbus
packet contains a value that is out of the expected
range.
Displays the number of commands that are not
appropriate for the field or record.
Displays the number of negative acknowledgments
due to problems with the device, so the command
was ignored.
Displays the control word in a bit coded format as
follows:
B0 = Start/Stop
B2 = Fault Reset
Displays the status word in a bit coded format as
follows:
I/O and Hardware (M5)
Description
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DPD01809
2016-06-07