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User manual SCAIME:
NU-Soft-eNod4F-E-0716_235704-C.doc
•
multi-bytes data : MSB first
4.4.2
Reading request
•
request
Address
Command
CR
CRC
1
Hex
byte
1
Hex
byte (command)
1
ASCII
byte (0D
H
)
1
Hex
byte
•
SCMBus response
Address
Status
Value
CR
CRC
1
Hex
byte
2
Hex
bytes
N
ASCII
Hex bytes
1
ASCII
byte (0D
H
)
1
Hex
byte
If the
‘decimal point position’
and the
‘unit’
settings are assigned to a non-null value, the response frame when
transmitting measurement contains the decimal point character (2E
H
) and the unit that is separated from the
measurement value by a space ASCII character (20
H
).
•
Fast SCMBus response
STX
Status word
Value
Cks
ETX
02
H
2 Hex bytes
3 signed Hex bytes (2’s
complement)
Σ of previous bytes
and b7 bit set to 1
03
H
Note:
Because values are encoded in signed hexadecimal bytes format (2’s complement) some data bytes can be
equal to
STX (02
H
) or ETX (03
H
) or DLE (10
H
) so before those specific bytes values a
DLE (10
H
)
byte is inserted. The
eNod4
address is not transmitted in the frame.
4.4.3
Functional command request (tare, zero...)
•
request :
Address
Command
CR
CRC
1
Hex
byte
1
Hex
byte (command)
1
ASCII
byte (0D
H
)
1
Hex
byte
•
response (SCMBus and fast SCMBus) :
Address
Command
CR
CRC
1
Hex
byte
1
Hex
byte (command)
1
ASCII
byte (0D
H
)
1
Hex
byte
If the command execution is successful,
eNod4
sends back the request frame that has been received as an
acknowledgement.
4.4.4
Error frame
In case of an error upon reception of a request,
eNod4
sends back an error frame that contains an error code:
•
response (SCMBus and fast SCMBus) :
Address
Error code
CR
CRC
1
Hex
byte
1
Hex
byte (command)
1
ASCII
byte (0D
H
)
1
Hex
byte
•
The error codes are listed below:
Error code
Meaning
Description
FE
H
unknown command
requested command is not supported by
eNod4
FF
H
error during command execution
ex. : tare when gross meas.<0
4.5
Address and Baud rate
Address and baud rate identical to Modbus RTU (See § Modbus RTU)
4.6
Product identification
Product identification identical to Modbus RTU (See § Modbus RTU)
4.7
Measurement transmission
Measurement transmission can be triggered by a master request but it might also be triggered and used through the
following options:
•
transmission triggered by a rising or falling edge on a logical input
