Note:
To do this, set the highest number
switch that is less than or equal to the
intended device address to ON. Then
continue setting lower numbered switches
until the total equals the intended address.
For example, if the intended device
address is 21, set switches 16, 4, and 1 to
ON (16+4+1= 21) and all other switches to
OFF.
3. Set a unique and sequential device address
for each of the expansion modules connected
on the SA or FC bus starting with device
address 4.
Note:
To ensure the best bus
performance, set sequential device
addresses with no gaps in the device
address range (4, 5, 6, 7, 8, 9, and so on).
The expansion modules do
not
need to be
physically connected on the bus in their
numerical device address order.
4. Write each expansion module's device
address on the white label below the DIP
switch block on the expansion module's
cover.
The following table describes the FC bus
and SA bus device addresses for Johnson
Controls MS/TP communications bus
applications.
Table 6: SA/FC bus device address descriptions
Device Address Use on Descriptions
0
(Switch 128 Off)
Reserved for FC Bus Supervisory Controller (not
for use on controllers or expansion modules).
1-3
(Switch 128 Off)
Reserved for peripheral devices (not for use on
controllers or expansion modules).
4-127
(Switch 128 Off)
Used for MSTP master devices (controllers and
expansion modules) that are hardwired to an
SA bus or FC bus.
Removing the expansion module
cover
About this task:
Important:
Electrostatic discharge can damage
expansion module components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid
damaging the expansion module.
Important:
Disconnect all power sources to
the expansion module before removing cover
and changing the position of any jumper or the
EOL switch on the expansion module. Failure to
disconnect power before changing a jumper or
EOL switch position can result in damage to the
expansion module and void any warranties.
The expansion module 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 expansion module cover,
complete the following steps:
1. Place your fingernails under the two cover lift
tabs 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 onto the latches until they snap into the
latched position.
Setting the End-of-Line (EOL) switch
About this task:
Each expansion module has an EOL switch, which
when set to ON, sets the expansion module as a
terminating device on the bus. See Figure 1 for the
EOL switch location. The default EOL switch position
is OFF.
Figure 9: End-of-Line switch positions
To set the EOL switch on an expansion module,
complete the following steps:
1. Determine the physical location of the
expansion module on the SA or FC bus.
2. Determine if the expansion module must be
set as a terminating device on the bus.
IOM3723 Input/Output Module Installation Guide
10
