SOMMAIRE
E 16
LOREME
12, rue des Potiers d'Etain - 57071 Metz
03.87.76.32.51 - Fax 03.87.76.32.52 - Email: [email protected] - Techni-
MODBUS TCP Communication
1) Features
Link:
Ethernet
Baud rate:
10/ 100 base T
Default IP address:
192.168.0.253
Port:
502
IP protocol:
Modbus TCP
Connector:
RJ45
Reading operation:
Code function 03, 04
Writing operation:
Not allowed
Data type:
Measure value, State of alarms.
Data format:
- Measure in floating point and 32 bits signed or unsigned integer format.
- State of alarms in 16 bits format.
2) Multi master using
The IPL.../CMTCP supports to be access by master with different IP address (6 max). However, care must be taken that
the average network load does not become too large. A network higher load can cause communication error due to the
traffic.
The average response time to a read request is around 50ms.
3) Data explanation
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.
3.1) Data format
- Data in 32 bits IEEE floating point format
Data are transmitted Most Significant Byte first, 4 bytes or 2 words long.
- Data in 32 bits signed or unsigned integer format.
Data are transmitted Most Significant Byte first, 4 bytes or 2 words long.
- Alarm data in 16bits integer (0 to 15), bit 0 for R1 and bit 1 for R2.
Data are transmitted Most significant byte first.
Sign Exponent
Mantisse
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
