Loreme IPL 144V, Configuration Handbook

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TABLE OF CONTENTS
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The time beyond which the device does not answer is called "TIME OUT" . It depends on the transmission parameters
(speed, format) and the type of the function asked (reading, writing). This time must be defined by the user and must be
superior to the answer time of the device.
A complete communication cycle includes :
- the question frame transmission Tq
- the device answer time Trep
- the answer frame transmission Tr
Three reasons might cause a TIME OUT: - wrong transmission data at the question frame time
- wrong configuration of the TIME OUT on the main station
- dependent station out-of-order.
3) Implementation:
3.1) Parameter:
Before starting up the RS485 MODBUS/JBUS communication, make sure that:
- the transmission speed is identical between the slaves (LOREME devices) and the main station.
- the parity is identical between the slaves (LOREME devices) and the main station.
- the addresses are correctly distributed among the stations (LOREME devices),
- the TIME OUT is correctly adjusted on the main station.
All the speed parameters , parity and address must be configured on the devices with the RS232 link.
The devices .configuration possibilities are the following ones:
- address: from 1 to 255
- speed: 600, 1200, 2400, 4800, 9600, 19200, 38400 bauds
- parity: even, odd, without.
- Data format
3.2) Interconnection:
The RS485 interface used allows to connect 128 dependent stations on the same network. For better operating condi-
tions (noise immunity), the network will have to be made up of a twisted pair.
4) Communication time:
4.1) Procedure:
Analysis of the times of communication for parameters of data transmission and for particular cases.
- reading measure phase, energy,
- energy reset,
- speed: 9600 bauds, parity: none.
4.2) Voltages reading:
Reading of 6 words (12 bytes) from address $A002 to $A007 (phase 1, 2, 3)
- 8 bytes question frame
Tq = (8 x 10) / 9600 = 8.33 ms
- Silence Ts = (3.5 x 10) / 9600 = 3.64 ms
- Processing Tt = 6 ms
- Emission 1
st
byte
Te1 = (1 x 10) / 9600 = 1.04 ms
- Answer time
Trep = Ts + Tt + Te1 = 10.68 ms
- Answer frame (17 bytes)
Tr = [(17 - 1) x 10] / 9600 = 16.66 ms
- Complete cycle
Tcyc = Tq + Trep + Tr = 35.65 ms