HART add-on module
7
4.3
General electrical
information
4.4
HART electrical
connections
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.
Please refer to the relevant handbook for other electrical connection information.
Terminals reserved for add-on modules:
MAG 5000 C: . . . . . . . 91 - 97
MAG 6000: . . . . . . . . . 91 - 97
MASS 6000: . . . . . . . . 91 - 100
Note
If the MASS 6000 is installed with extra outputs, i.e. have 3 current outputs, 2 digital outputs and
2 relay outputs, then it is not possible to install a HART interface. This is because the extra outputs
takes up all terminals.
The following table shows the connection layout for the USM II HART module:
In order to have the HART FSK signal combined with the Current output, two connections must
be made. Terminal 31 must be connected to 91 and terminal 32 must be connected to 92.
Electrical wirering can be seen in the drawing below.
4.5
Current output
A true HART signal consists of a Current output combined with a HART FSK signal. In order to
achieve this, connections must be made according to the chapter: HART electrical connections.
When a HART module is installed the Current output changes its behaviour in order to comply
with HART. This will be explained in the following chapters.
Terminal
Description
91
HART FSK
92
HART FSK signal -
31
Current
32
Current output -
Shield/PE
Shield
4.5.1 MAG 5000 C/6000
When the HART module is inserted, it automatically turns on the Current output with its factory
settings. The HART device with address „0“ is the only device that is allowed to control the Current
output loop.
Single point:
When only one device is connected to the network, the HART short address should be set to 0.
The Current output is fixed to Volume flow, which is the only process value in this device. Volume
flow is also mapped to the PV reading.
4. Product interfaces
