Setup and Adjustments
Setting the device address
Metasys
expansion modules are master devices
on MS/TP (SA or FC) buses. Before operating an
expansion module on a bus, set a valid and unique
device address for each expansion module on
the bus. You set an expansion module's device
address by setting the positions of the switches on
the DIP switch block at the top of the expansion
module. Device addresses 4 through 127 are the
valid addresses for these expansion modules.
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.
The DIP switch block has eight switches numbered
128, 64, 32, 16, 8, 4, 2, and 1. Switches 64 through 1
are device address switches. Switch 128 must be set
to
OFF
for all hard-wired SA and FC Bus applications.
Figure 8: Device address DIP switch Block set to
address 21
Note:
Metasys
field controllers ship with switch
128 ON and the remaining address switches
off rendering the controllers wired subordinate
devices, which do not operate on MSTP buses,
but do not interfere with bus operation. Set
a valid and unique device address on the
expansion module before applying power to
the expansion module on the bus.
To set the device addresses on
Metasys
expansion modules, complete the following
steps:
1. Set
all
of the switches on the address DIP
switch block (128 through 1) to OFF.
2. Set one or more of the seven address switches
(64 though 1) to ON, so that the sum of the
switch numbers set to ON equals the intended
device address, and ensure that switch 128
remains set to OFF.
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 module 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 (for example, 4, 5, 6, 7, 8,
9). The controllers/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.
Removing the expansion module
cover
Important:
Electrostatic discharge can damage
expansion module components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid
damaging the expansion module.
IOM3733 Input/Output Module Installation Guide
10