Delta RMC101 - Manual (Page 496)

RMC100 and RMCWin User Manual
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115,200 475 3250
57,600 950 4000
38,400 1900 4000
19,200 3750 4000
9,600 4000 4000
4,800 4000 4000
2,400 4000 4000
5.5.2.7 RS-422/485 Termination and Biasing
Termination and Biasing are concepts that only apply to differential wiring. As such, they only
apply to RS-422 and RS-485 and not RS-232. The Termination and Biasing concepts are
described in detail below. First, however, we will describe the options provided by the RMC
SERIAL module.
For RMC SERIAL modules with hardware revision 2 or later, biasing and termination can be
independently selected for both wire pairs. For RMC SERIAL hardware revision 1, biasing and
termination must be enabled and disabled together and are only available on the Tx/Rx wire pair
and not on the Tx pair.
To change the termination and biasing options for the RMC SERIAL module:
1. On the Tools menu, click Module Configuration.
2. In the Slots list, click the Serial line.
3. Click Slot Options.
4. In the Serial Module Options dialog box, ensure that RS-422/RS-485 (4-wire) or RS-485 (2-wire)
is selected.
5. Click Advanced.
6. Check or un-check the Enable Biasing Circuit and Enable Termination check boxes for the
transmitter and receiver (for 4-wire) or transceiver (for 2-wire). The diagram in the dialog box will
update accordingly.
Note: As described above, hardware revision 1 does not allow biasing and termination to be
independently selected, and only allows enabling them on the Rx/Tx pair.
7. Click OK.
8. Click Update RMC.
This step will save the settings to Flash memory.
The Update Module Configuration dialog box will be displayed to indicate the progress. If the
module could not be reset automatically, you may be prompted to reset the module manually.
9. In the RMC Configuration dialog box, click Close.
The values of the resisters and capacitors in version 2 and later of the RMC SERIAL's
termination/biasing circuit are shown in the diagram below: