Setting the device address - Metasys - MS-FAC3611 - Field Device - FAC36 Advanced Application Field Equipment Controller

About this task

Metasys expansion modules are master devices on MS/TP (SA or FC) buses. Before operating an expansion module on a bus, you must 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 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. Switch 128 must be set to OFF for all hard-wired SA and FC Bus applications

Figure 1. Device address DIP switch block set to address 21

Note: Metasys controllers ship with switch 128 ON and the remaining address switches OFF rendering the controllers wired subordinate devices, which do not operate on MS/TP 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:

Procedure

Set all of the switches on the address DIP switch block (128 through 1) to OFF.
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.
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.

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 1. 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.