CHAPTER 2: QUICK START
SNAP PAC S-Series User’s Guide
19
19
Configuring RS-485 Connections on SNAP-PAC-S1 Controllers
RS-485 bias and termination settings are config-
ured using two DIP switches located on the top
of the controller.
Bias
: Only one device on an RS-485 network
should have bias turned on. If there are no other
devices with bias active, you can set the SNAP
PAC S-series controller to do so.
Termination:
Termination settings depend on
the controller’s location on the RS-485 network.
Settings for different controller locations are
shown in the table below.
Configuring RS-485 Connections on SNAP-PAC-S2 Controllers
The serial ports on SNAP-PAC-S2 controllers are software configurable using PAC Manager. This
includes mode, termination, and bias. For more information, see the PAC Manager User’s Guide. See
also,
“Assigning Serial Ports on SNAP-PAC-S2 Controllers” on page 24
.
Wiring the 10-pin Serial Connector on SNAP-PAC-S1 Controllers
Serial ports1 and 2 on SNAP-PAC-S1 controllers share a 10-pin pluggable connector (Phoenix
Contact, part number FK-MC 0.5 - 2.5, supplied with the controller). When inserting and removing
wire leads into this connector, do the following:
1.
Completely depress the small orange tab for the appropriate opening with a small screwdriver.
2.
While holding the tab down with the screwdriver, insert or remove the wire as needed.
3.
Release the orange tab.
For a pinout of the connector, see
“SNAP-PAC-S1 and -FM Connectors, Indicators, and Pinouts” on
page 53
.
SNAP PAC S-series controller
location on RS-485 network
RS-485
termination
Termination
Active
Termination
Inactive
Switch
Position
Description
1
ON
Bias: active
OFF
Bias: inactive
2
ON
Termination: active
OFF
Termination: inactive
(Portion of top view)
DIP switches
At the End
In the Middle
(floating)
