Modbus alarm handling

The CSV features an alarm list as well as a fault log.

Alarm list

The alarm list is available on Modbus since firmware version 2.21 of the CSV and allows to read out the actual alarms including warnings, criticals and faults. It allows thereby - on the one hand - to display the actual alarms, and on the other it provides the basis for the system controller to react in order to avoid a compressor fault.

When power-cycling the frequency inverter or providing a reset command, the inactive alarms will be cleared from the list. The alarm list is identical and shared between the IQ products CSV, CM-RC, CM-SW and SE-i1.

Register	Name	Description	Type
11201 (I) .. 11210 (I)	Alarm 1 .. 10	Alarms are ranked in the alarm list according to severity: alarm 1 is highest ranking, alarm 10 is lowest ranking. Bit 0 .. 9 (binary to decimal): Index number, see in BEST Software under "Product" --> "Documentation" --> "Alarms" for the translation of index numbers into alarm texts. The table can be exported as csv file via the "Export..." button in the top menu all the way to the right. Bit 10 .. 12 (binary to decimal): Alarm severity 3 = Warning 4 = Critical 5 = Fault Bit 13: Reserved Bit 14 .. 15 (binary to decimal): Alarm state 1 = Inactive 2 = Active 3 = Set (alarm condition is present) Excel tool for decoding: An Excel tool which allows to decode actual alarm values received via Modbus and visualizes the decoding step by step can be downloaded here.	uint16

Name

Description

Type

11201 (I) .. 11210 (I)

Alarm 1 .. 10

Alarms are ranked in the alarm list according to severity:
alarm 1 is highest ranking, alarm 10 is lowest ranking.

Bit 0 .. 9 (binary to decimal): Index number, see in BEST Software under "Product" --> "Documentation" --> "Alarms" for the translation of index numbers into alarm texts. The table can be exported as csv file via the "Export..." button in the top menu all the way to the right.
Bit 10 .. 12 (binary to decimal): Alarm severity
3 = Warning
4 = Critical
5 = Fault
Bit 13: Reserved
Bit 14 .. 15 (binary to decimal): Alarm state
1 = Inactive
2 = Active
3 = Set (alarm condition is present)

Excel tool for decoding:

An Excel tool which allows to decode actual alarm values received via Modbus and visualizes the decoding step by step can be downloaded here.

uint16

Fault log

The fault log contains the 10 latest detected different faults. A fault condition can be detected several times, and the number of faults is stored. When a new fault is detected, it is stored in fault log 1. If there should be a fault in fault log 1, it is pushed to fault log 2 and so on. If there should be one in fault log 10, it is deleted.

The fault log group contains information about the alarm code of the fault, number of times the specific fault has occurred (310X2), date (310X3 and 310X4) and time (310X5) for the last occurrence of the fault.

Fault log 1 .. 10 have the same layout, however the Modbus register increases by 10 from one fault log entry to the next.

(*): If there is an active fault bit in the fault word, the fault log 1 contains the latest alarm entry.
Register	Name	Description	Type
31000 (I)	Alarm code 1 (*)	Alarm code of the fault log 1	uint16
310X2 (I)	Fault counter	Number of times the fault has occurred	uint16
310X3 (I)	Year	Year of last fault occurrence	uint16
310X4 (I)	Month and day	Month and day of last fault occurrence: Bit 0 .. 7: Day of month Bit 8 .. 15: Month	uint16
310X5 (I)	Hour and minute	Hour and minute of last fault occurrence: Bit 0 .. 7: Minute Bit 8 .. 15: Hour	uint16

Alarm severity types

There are the following alarm severity types:

Fault :
If a fault alarm condition is detected, the CSV will coast and release the compressor motor.

Critical :
If a critical alarm condition is detected, operation may continue but for a limited time or with reduced performance.

Warning :
A warning is signalled when a condition occurs which may require attention but is not severe enough to stop operation of the compressor. The compressor keeps running.

Alarm reset types

Auto:

The fault is reset automatically when the fault condition is no longer present.

Timed:

The fault is reset automatically when the fault condition is no longer present and the configurable interval "Timed reset interval" has counted down.
By providing a manual reset command, the timed reset interval time can be cancelled in case the fault condition is no longer present.
Repetitive timed reset faults will be limited by the external reset faults "10-00 Too many identical timed reset faults in 24 hours" and "10-01 Too many timed reset faults in 1 hour".

External:

In case of an external reset fault, the system must be checked before unlocking.
The fault must be reset by reset command when the fault condition is no longer present.

Restart:

A power cycle is required to reset the fault.

Possibilities for providing a reset command

The CSV can be unlocked in various ways:

With a Modbus command (see in BEST Software unter "Documentation" --> "Modbus" --> Tab "Control & Status Word" --> Serial Control Word - this is possible even if Modbus control is not activated).
With the BEST Software in the menu "Alarms" --> "Reset".
By activating the digital input DI3.
Power cycle the frequency inverter by interrupting the mains supply for at least 140 seconds. Plug off the BEST converter if it is connected, because otherwise the control board will be kept powered by the BEST converter.

NOTICE

Compressor damage!

Repeated resetting of external reset faults may lead to breakdown of the compressor if the cause is not resolved.