Antona Corporation
7
(818)783-4299
For site lengths greater than 150 feet, resister termination across the remote receive pair
end of the cable may be necessary. The ANC-6185 has a ½W 120 ohm termination resister
built in that can be placed across the receive wire pair by setting jumper 4 (JP4) located over the
transmit/receive setting jumpers (JP5/6). An external DC power source may be necessary to
supply the additional current that the adapter may need when terminating resisters are installed
on the receive/transmit wire pairs. Some equipment have internally connected circuitry for 120
ohm resister termination. If So, then even if the separation distance is less than 150 feet, it may
be necessary to provide an external source of DC. Often equipment also allows the user to
disconnect the internal termination network for short cable runs. See Appendix B, the upper
middle of the schematic for the location of JP4.
Figure 3 – terminating resister jumpering
Tx - Rx Pin Reverse Jumpers – JP5/JP6
These two jumper sets, designated JP5 and JP6 on the ANC-6185 circuit board and
schematic, allow the designer to swap the transmit and receive pairs on the RS-485/422 side of
the adapter. The configuration as shipped from Antona is set for ‘master’. Figure 1 shows the
jumper locations on ANC-6185 circuit board and figure 4 below shows the jumper settings. The
user can move all four jumpers on the card from the horizontal ‘master’ (controller) configuration
to the vertical ‘server’ (remote) configuration. All four jumpers must be changed to either all
horizontal or all vertical for proper adapter operation as shown in figure 4 below, and on the
schematic of Appendix B. For normal interfacing, use the jumpering of JP5/6 as shipped. For
other interfaces, the user hand-wires a cable assembly from the RS-485/422 piece of equipment
to the Antona adapter using either discrete wires (T version) or a male RJ-45 (R version). The
only difference between the master and server setting is the jumper positions of JP5 and JP6
within the adapter.
The electronics are exactly the same, only the 2 transmit and 2 receive signal
lines are exchanged on the RS-485/422 side of the adapter
. This feature is probably most
useful on the ‘R’ RJ-45 version adapter where a pre-made ethernet compatible cable may be
used. On the ‘T’ terminal block version, the designer just wires to the appropriate terminal
figure 4 – Tx/Rc Pin Reverse Jumpers
block pin per the signal function and changing the jumpers for opposite ends of the cable is not
needed.
