Technical information
9
Fieldbus Protocols The Tank Side Monitor NRF590 supports all of the following industry standard communication protocols
allowing it to be integrated with existing instrumentation and connect to host computer systems without the
need for additional hardware. These protocols allow for piece-by-piece replacement and upgrading of older
technologies to modern radar solutions.
Sakura V1
V1 protocol provides a standard form of digital communication via a two-wire system. V1 was brought to the
market by Sakura Endress and meets the demands of the Japanese market.
The Tank Side Monitor implementation of the V1 slave protocol supports various old and new V1 protocols:
•V1 (new V1)
• MDP (old V1)
• BBB (old V1)
• MIC+232 (old V1) (in preparation)
EIA-485 (RS485) Modbus
In Modbus, the flow of data between two devices uses a master/slave protocol. The NRF590 acts as a Modbus
slave and runs on the EIA-485 (RS) version of the MODBUS communications board. Modbus provides Varec
MFT parameter mapping for easier setup in retrofit applications. It provides direct connection to PLC and DCS
systems.
Whessoematic WM550
The WM550 protocol provides a standard form of digital communication via dual current loops. WM550 was
developed by Endress+Hauser (formerly Whessoe) to facilitate communications to transmitters installed on
mechanical float and tape gauges. It is a two-wire system and the only protocol with a redundant loop.
BPM
The Bi-Phase Mark (BPM) protocol provides compatibility to Enraf systems by emulating the Enraf GPU-BPM
protocol. The NRF590 is fully compatible to ENRAF (802, 812), 811, 854 and 954 series servo gauges, 813
MGT (mechanical gauge transmitter), 872, 873 and 973 series Radar gauges, 874 AIM (Analogue Input
Module) and the 875 VCU (Valve Command Unit).
Mark/Space
The Mark/Space protocol provides compatibility with Varec transmitters using a standard form of digital
communication via a voltage mode bus. Mark/Space was developed to facilitate communication to transmitters
installed on mechanical float and tape gauges. It supports product level, temperature and discrete inputs.
L&J Tankway
L&J Tankway protocol provides a standard form of digital communication via a voltage mode bus. Tankway
supports product level, temperature and discrete inputs.
GPE
GPE protocol provides a standard form of digital communication via a current loop. It is compatible with L&J
and GPE mechanical float and tape and servo instrumentation.