ABB REM 610 Technical Reference Manual page 68

REM 610
68
Motor Protection Relay
Technical Reference Manual
The Modbus protocol provides the following diagnostic counters:
Table 4.1.14.2-3 Diagnostic counters
Name
Bus message count
Bus communication error
count
Bus exception error count
Slave message count
Slave no response count
Slave NACK response
count
Bus character overrun count The number of messages addressed to the slave for which it
The following exception codes may be generated by the Modbus protocol:
Table 4.1.14.2-4 Possible exception codes
Code Name
01 Illegal function
02 Illegal data
address
03 Illegal data value
04 Slave device
failure
Note!
If an "Illegal data value" exception response is generated when attempting to preset
multiple registers, the contents of the register to which an illegal value has been
imposed and of the following registers will not be changed. Registers which have
already been preset will not be restored.
User-defined registers
Reading of unwanted data in a data block wastes bandwidth and complicates data
interpretation. For optimum efficiency in Modbus communication, data has
therefore been organized into consecutive blocks. In addition, a set of programmable
user-defined registers (UDR) has been defined in the holding register area.
The first sixteen holding registers, i.e. HR1...16, are user-defined registers. The
UDRs can be linked to any holding register, except for HR721...727, using SPA
parameters 504V1...504V16. However, one UDR cannot be linked to another, i.e.
linking cannot be nested. Each parameter contains the address of the holding register
to which the UDR is linked.
Description
The number of messages in the communications system
detected by the slave since its last restart, clear counters
operation or power up.
The number of CRC or LRC errors encountered by the slave
since its last restart, clear counters operation or power up.
The number of Modbus exception responses sent by the slave
since its last restart, clear counters operation or power up.
The number of messages addressed to the slave or broadcast
which the slave has processed since its last restart, clear
counters operation or power up.
The number of messages addressed to the slave for which a
response (neither a normal response nor an exception
response) has not been sent since its last restart, clear
counters operation or power up.
The number of messages addressed to the slave for which a
NACK response has been sent.
has not been able to send a response due to a character
overrun since its last restart, clear counters operation or power
up.
Description
The slave does not support the requested function.
The slave does not support the data address or the number of
items in the query is incorrect.
A value contained in the query data field is out of range.
An unrecoverable error has occurred while the slave was
attempting to perform the requested task.
1MRS 752263-MUM