Removing The Controller Cover; Setting The End-Of-Line (Eol) Switch - Johnson Controls Metasys MS-IOM4711 Series Installation Instructions Manual

Table 6: SA/FC Bus Device Address Descriptions
Device Use on Description
Address
0 to 3 Reserved addresses for wired slave devices
(not for use on controllers).
(Switch
128 ON) Note: Metasys field controllers ship with switch
128 ON and the remaining address switches
off rendering the controllers wired slave
devices, which do not operate on MS/TP
buses.
4 to 127 Valid for MS/TP Master controllers on wireless
FC Buses only.
(Switch
128 ON) Note: Do not connect a controller with switch
128 ON to an active (hard-wired) SA or FC
Bus. When a controller with switch 128 ON
and a device address from 4 to 127 is
connected to a wired field bus, the entire field
bus is rendered inoperable until the controller
is disconnected or switch 128 is set to Off.

Removing the Controller Cover

Important: Electrostatic discharge can damage
controller components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid
damaging the controller.
Important: Disconnect all power sources to the
controller before removing cover and
changing the position of any jumper or the
EOL switch on the controller. Failure to
disconnect power before changing a jumper
or EOL switch position can result in damage
to the controller and void any warranties.
The controller cover is held in place by four plastic latches
that extend from the base and snap into slots on the
inside of the housing cover.
To remove the controller cover:
1. Place your fingernails under the two cover lift tabs
(Figure 3) on the sides of the housing cover and
gently pry the top of the cover away from the base to
release the cover from the two upper latches.
2. Pivot the top of the cover further to release it from the
lower two latches.
3. Replace the cover by placing it squarely over the
base, and then gently and evenly push the cover on
to the latches until they snap into the latched position.
IOM47 Input/Output Module Installation Instructions
Figure 10: IOM47 with Cover Removed Showing EOL
Switch and Jumper Positions

Setting the End-of-Line (EOL) Switch

Each controller has an EOL switch, which, when set to
ON, sets the controller as a terminating device on the
bus. See Figure 10 for the EOL switch location. The
default EOL switch position is Off.
Figure 11: End-of-Line Switch Positions
To set the EOL switch on a controller:
1. Determine the physical location of the controller on
the SA or FC bus.
2. Determine if the controller must be set as a
terminating device on the bus.
Note: The EOL termination rules for SA buses and
FC buses are different. Refer to the MS/TP
Communications Bus Technical Bulletin
(LIT-12011034) for detailed information
regarding EOL termination rules and EOL
switch settings on SA and FC buses.
3. If the controller is a terminating device on the FC bus,
set the EOL switch to ON. If the controller is not a
terminating device on the bus, set the EOL switch to
Off.
When a controller is connected to power with its EOL
switch set to ON, the amber EOL LED on the
controller cover is lit.
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