Connecting - Siemens SITRANS F Operating Instructions Manual

Connecting

On the electrical termination boards for USM-II transmitters, additional input/output terminals
have been reserved for add-on module functions. The numbering range of these terminals is
as follows, but how many are actually used depends on the type of add-on module.
Additional terminals reserved for add-on modules:
● MAG 6000: 91 - 97
● MASS 6000: 91 – 100
Please refer to the relevant product operating instruction for other electrical connection
information.
Note
Shielding
Always shield a Modbus over Serial Line Cable. At one end of each cable its shield must be
connected to protective ground. If a connector is used at this end, the shell of the connector
is connected to the shield of the cable.
Note
Cable specifications
A RS485-Modbus must use a balanced pair (for D0-D1) and a third wire (for the Common).
For the balanced pairs used in an RS485-system, a Characteristic Impedance with a value
between 100 and 120 Ohms must be used.
Modbus RTU RS485
Operating Instructions, 06/2010, A5E00753974-04
Note
The standard inputs and outputs continue to function and are not affected by the
presence of an add-on module. Any existing transmitter electrical connections remain
undisturbed. The MASS 6000 with extra outputs, i.e. 3 current outputs, cannot be
extended with an add-on module
WARNING
Only authorized personnel are allowed to carry to carry out work on electrical
connections.
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