Lumel SMC series, User Manual

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20
Data Field:
In the correct response, the slave device can return data on the data field (some information requested by
the master unit).
In the erroneous response, the slave device returns the terror code on the data field. It defines the slave
device conditions, which causes the error.
An example of master device request and erroneous slave device response is presented below. Data are in
the hexadecimal shape.
Example: request
slave
address
function variable
address
Hi
variable
address
Lo
number of
variables
Hi
number of
variables
Lo
checksum
0A 01 04 A1 00 01 4F LRC
Example: erroneous error
slave
address
function error
code
checksum
0A 81 01 73 LRC
In this example, the master device addresses the request to the slave unit numbered 10 (oHa).
The function with the code (01) is not implemented in the concentrator, then the device returns the erroneous
response with the error code nr 01. It indicates the forbidden function in the slave device. Possible error
codes and their meanings are presented in the table below.
code meaning
01 forbidden function
02 forbidden data address
03 forbidden data value
04 request being in realization
05 impossible request realization
8. TECHNICAL DATA
Serial port I:
- baud rate 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200 bit/s
- mode
ASCII: 8N1, 7E1, 7O1,7N2
RTU: 8N2, 8 E1, 8O1, 8N1
- interface 2 x RS-485
Serial port II:
- baud rate 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200 bit/s
- mode
ASCII: 8N1, 7E1, 7O1,7N2
RTU: 8N2, 8 E1, 8O1, 8N1
- interface RS-485, RS-232
USB 1.1 – wire no longer than 3 m
Transmission protocol: MODBUS – ASCII, RTU
Power consumption
≤
4 VA