VEGA VEGAPULS 62 (≥ 2.0.0 - ≥ 4.0.0) Modbus and Levelmaster protocol Approval according to LPR radio standard - Manual (Page 69)

10 .2 Basics Modbus
Bus description
The Modbus protocol is a communication protocol for the communication between instruments. It is
based on a Master/Slave or Client/Server architecture. By means of Modbus, a Master and several
Slaves can be connected. Each bus participant has an unambiguous address and can send
messages to the bus. This is initiated by the Master, the addessed Slave answers. The versions
Ethernet and serial (EIA-232 and EIA-485) as well as the modes ASCII, TCP and RTU are available
for the data transfer. In the RTU and ASCII mode interesting here, data will be transmitted in binary
form. The telegram consists generally of the address, the function, the data as well as the
transmission check.
Bus architecture
In the version Modbus RTU, up to 32 participants can be connected to the bus. The length of the
twisted two-wire cable can be up to 1200 m. The bus must be terminated on both sides at the last bus
participant with a terminating resistor of 120 Ohm. The resistor is already integrated in the
VEGAPULS
62 and is activated/deactivated via a slide switch.
4
1
3 3 3
2
+
+
power supply
MODBUS
D0 D1 IS GND
USB
+
+
power supply
MODBUS
D0 D1 IS GND
USB
+
+
power supply
MODBUS
D0 D1 IS GND
USB
1 3 4 5 2 off on ( )
(
)
(-)
(-) 1 3 4 5 2 off on ( )
(
)
(-)
(-) 1 3 4 5 2 off on ( )
(
)
(-)
(-)
Fig. 45: Bus architecture Modbus
1 RTU
2 Connection resistor
3 Bus participant
4 Voltage supply
Protocol description
The VEGAPULS 62 is suitable for connection to the following RTUs with Modbus RTU or ASCII
protocol.
VEGAPULS 62 • Approval according to LPR radio standard 69
10 Supplement
41722
-EN
-120706