Interface/Protocols - Bender ISOMETER isoEV425 Manual

Function

3.2.12 Interface/protocols

The ISOMETER® uses the serial hardware interface RS-485 with the following
protocols:
BMS
 
The BMS protocol is an essential component of the Bender measuring
device interface (BMS bus protocol). Data is transferred using ASCII
characters.
Modbus RTU
 
Modbus RTU is an application layer messaging protocol and it provides
Master/Slave communication between devices that are connected
together via bus systems and networks. Modbus RTU messages have a
16-bit CRC (Cyclic Redundant Checksum), which guarantees reliability.
IsoData
 
The ISOMETER® continously sends an ASCII data string with a cycle of
approximately 1 second. Communication with the ISOMETER® within
this mode is not possible and no additional transmitter may be connect-
ed to the RS-485 bus cable. The ASCII data string for the ISOMETER® is
described in
The device address, baud rate and parity for the interface protocols are con-
figured in the "out" menu.
isoEV425_D00126_09_M_XXEN/03.2019
Chapter 9.
With "Adr = 0", the menu entries baud rate and parity are not
shown in the menu and the IsoData protocol is activated.
With a valid bus address (i.e. not equal to 0), the menu item
"baud rate" is displayed in the menu. The parameter value
"---" for the baud rate indicates the activated BMS protocol. In
this event, the baud rate for the BMS protocol is set to
9,600 baud. If the baud rate is set unequal to "---", the
Modbus protocol is activated with a configurable baud rate.
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