Memory Markers; Communication Errors - WEG SCA06 User Manual

It is necessary to know the device list of parameters to be able to operate the equipment. Thus, it is possible to
identify what data are needed for the status monitoring and the control of the functions. The main parameters are:
Monitoring (reading):
P0002 (holding register 2): Motor speed
P0052 (holding register 52): Fractions of revolution
Command (writing):
P0099 (holding register 99): Enable
P0121 (holding register 121): Speed reference
P1100 (holding register 1100): User parameter 1100
Refer to the Programming Manual for a complete parameter list of the equipment.
NOTE!
All the parameters are treated as holding registers. Depending on the master that is used, those
registers are referenced starting from the base address 40000 or 4x. In this case, the address
that must be programmed in the master for a parameter is the address showed in the table above
added to the base address. Refer to the master documentation to find out how to access holding
registers.
It should be noted that read-only parameters can only be read from the equipment, while other
parameters can be read and written through the network.
7.3.2

Memory Markers

Besides the parameters, other types of data as bit markers, word or float, can also be accessed using the Modbus
protocol. Those markers are used mainly by the SoftPLC function, available for the SCA06. Refer to the SoftPLC
documentation for the description of those markers, as well as for the addresses via Modbus.
7.4

COMMUNICATION ERRORS

Communication errors may occur in the transmission of telegrams, as well as in the contents of the transmitted
telegrams. Transmission and connection errors are directly processed by the Ethernet interface and by the TCP/IP
protocol.
In the event of a successful reception, during the treatment of the telegram, the server may detect problems and send
an error message, indicating the kind of problem found:
Table 7.3: Parameters Access - Holding Registers
Parameter Modbus data address (decimal)
P0000
P0001
. .
. .
. .
P0100
. .
. .
. .
0
1
100
Modbus TCP
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