VEGA VEGABAR 81 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 63)

63
10 Supplement
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-131107
Accuracy ±1 °C (1.8 °F)
Voltage supply
Operating voltage
8 … 30 V DC
Power consumption < 500 mW
Interpolation protection Integrated
Potential connections in the instrument
Electronics
Not non-floating
Ground terminal Galvanically connected with the process fitting
Electrical protective measures
Housing material Version IP-protection class NEMA protection
Plastic Single chamber IP 66/IP 67 NEMA 4X/6P
Double chamber IP 66/IP 67 NEMA 4X
Aluminium Single chamber IP 66/IP 68 (0.2 bar)
IP 68 (1 bar) NEMA 4X/6P
-
Double chamber IP 66/IP 67
IP 66/IP 68 (0.2 bar) NEMA 4X
NEMA 4X
Stainless steel, electro-
polished
Single chamber
Single chamber IP 69K
IP 66/IP 68 (0.2 bar) -
NEMA 4X/6P
Stainless steel, investment
casting
Single chamber IP 66/IP 68 (0.2 bar)
IP 68 (1 bar) NEMA 4X/6P
NEMA 4X
Double chamber IP 66/IP 67
IP 66/IP 68 (0.2 bar) NEMA 4X
NEMA 4X
Stainless steel Transmitter for external
housing
IP 68 (25 bar) -
Overvoltage category III
Protection class II
Approvals
Instruments with approvals can have different technical data depending on the version.
For that reason the associated approval documents of these instruments must be carefully noted.
They are part of the delivery or can be downloaded under www.vega.com and "VEGA Tools" as
well as under "Downloads" and "Approvals".
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 mes-
sages to the bus. This is initiated by the Master, the addessed Slave answers. The versions Ethernet