User manual for RTD,TC,mV/4-20mA converter module SPT-86L
03h
- illegal data value
08h
- no write permission (see ”
ModbusAccess
”)
A0h
- exceed of upper border of input range
60h
- exceed of lower border of input range
C0h
- sensor failure,
10h
- incorrectly defined user multipoint characteristic,
20h
- waiting for the first measurement after changing the configuration.
A0h, 60h, C0h, 10h, and 20h codes can appear only during reg. 01h is reading by 03h
function (read of a single register).
8.3.
EXAMPLES OF QUERY/ANSWER FRAMES
Examples apply for device with address 1. All values are represent hexadecimal.
Field description:
ADDR
Device address on modbus network
FUNC
Function code
REG H,L
Starting address (address of first register to read/write, Hi and Lo byte)
COUNT H,L
No. of registers to read/write (Hi and Lo byte)
BYTE C
Data byte count in answer frame
DATA H,L
Data byte (Hi and Lo byte)
CRC L,H
CRC
error check (Hi and Lo byte)
1. Read of the measured value, SPT-86L device address = 01h:
ADDR
FUNC
REG H,L
COUNT H,L
CRC L,H
01
03
00
01
00
01
D5
CA
a) The answer (we assume that the measure result is not out of range):
ADDR
FUNC
BYTE C
DATA H,L
CRC L,H
01
03
02
00
FF
F8
04
DATA H, L - measured value = 255, no decimal point.
Decimal point position can be read from reg. 03h.
b) The answer (if an error occur):
ADDR FUNC
ERROR
CRC L,H
01
83
60
41
18
ERROR - error code = 60h, bottom border of the measurement range is exceeded
21
