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User manual SCAIME:
NU-Soft-eNod4F-E-0716_235704-C.doc
•
slave response :
slave address
06
H
register offset
data
CRC16
1 byte
1 byte
2 bytes
2 bytes
2 bytes
3.4.3
Function (10H)
–
preset multiple registers (N = 30 max)
•
request command sent to the slave :
slave address
10
H
starting register
offset
N registers
NB
Data 1
…
CRC16
1 byte
1 byte
2 bytes
2 bytes
1 byte
2 bytes
2 bytes
2 bytes
•
slave response :
slave address
10
H
starting register
offset
N registers
CRC16
1 byte
1 byte
2 bytes
2 bytes
2 bytes
3.4.4
Error frames
•
frame format in case of a transaction error :
slave address
Function code
+ 80
H
error code
CRC16
1 byte
1 byte
1 byte
2 bytes
•
Error codes meaning :
Error code
Meaning
description
01
H
illegal function
Modbus-RTU function not supported by eNod4
02
H
illegal data address
register address requested out of
eNod4
register table
03
H
illegal data value
forbidden data values for the requested register
04
H
eNod4
not ready
eNod4
is not ready to answer (for example measurement
request during a taring operation)
3.5
Address and Baud rate
Address Modbus RTU
Meaning
Access
Type
0x0001
Address and Baud rate
RO
Uint
Reads the address and baud rate selected on the front panel via the rotary switches and dipswitches.
3.6
Product identification
Software and product versions of the
eNod4
are accessible via Modbus RTU.
Address Modbus RTU
Meaning
Access
Type
0x0000
SW and product version
RO
Uint
The 12 LSB bits define the software version (073
H
= 115) and the 4 MSB bits define the product version (6
H
for the
eNod4
).
3.7
Measurement transmission
As a master/slave protocol, measurement transmission in Modbus protocol is only done on master request.
3.8
EEPROM error management
Functioning and calibration parameters are stored in EEPROM. After every reset the entireness of parameters stored
in EEPROM is checked. If a default appears, measurements are set to 0xFFFF and default is pointed out in
measurement status.