SOMMAIRE
E 14
LOREME
12, rue des Potiers d'Etain - 57071 Metz
03.87.76.32.51 - Fax 03.87.76.32.52 - Email: [email protected] - Techni-
1) Feature
Protocol:
MODBUS RTU
Link:
RS485
Baudrate:
1200 to 38400 bds
Address:
1 to 255
Reading request:
function code 03,04
Type of data:
electrical measurement, status of alarms.
data format:
Measure in floating point and 32 bits signed or unsigned integer format.
response time:
The delay for a reading request is <40ms
2) Data
2.1) Available data
All measures are accessible in reading mode. Data's are available in different formats:
- 2 words, 4 bytes, for measures in the 32 bits IEEE floating point format.
- 2 words, 4 bytes, for measures in the 32 bits integer format.
- 1 word, 2 bytes, for the alarms state.
2.2) Format of data
- Data in 32 bits IEEE floating point format
- Data send Most Significant Byte first (word 1: ex mantissa MSB, word 2: mantissa)
- Data in 32 bits integer signed or not.
- Data send MSB first. 4 bytes or 2 words long.
- Data in 16 bits integer format for status of alarm R1 (bit0) and R2 (bit1).
- Data send MSB first.
3)
Exception frame:
If the slave receive an corrupted frame (CRC16 or parity), it doesn’t answer. If it is a frame error (data address, function,
value), the slave send a exception frame. The exception frame is a 5 bytes frame long.
Details of the exception frame: The function code of the exception frame is identical to the question frame, but this MSB
bit is set to 1. The error code indicate the reason of the exception frame
Error code
Details
$01
Function code not allowed. Only the function code $03 or $04 are used by the INL100-150
(register reading function).
$02
Data address not allowed
$04
Slave busy. The internal communication slot is not in connection with the measure part.
RS485 MODBUS communication
MSW
LSW
byte 1
byte 2
byte 3
byte 4
31
24 23
16 15
8 7
0
Byte 1
Byte 2
15
MSB
8 7
LSB
0
