Setting the device address - BCPro - Facility Explorer - CH-PCX3733-0 - Field Device - FX-PCX37 Expansion Input/Output Module

PCX3733 Expansion Input/Output Module Installation Guide

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FX-PCX37 Expansion Input/Output Module
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Installation Guide
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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 1. SA/FC Bus Device Address Descriptions
Device Address Use on Descriptions

(Switch 128 Off)

Reserved for FC Bus Supervisory Controller (not for use on controllers or expansion modules).


(Switch 128 Off)

Reserved for peripheral devices (not for use on controllers or expansion modules).

(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 is a mode switch that enables an expansion module to operate on an FX-ZFR/ZFR Pro Series Wireless Field Bus. Switch 128 must be set to OFF for all hard-wired SA and FC Bus applications. Set switch 128 to ON for wireless FC bus applications only.

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

Note: Expansion modules ship with switch 128 ON and the remaining address switches off rendering the expansion module 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 an expansion modules:

  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 switch 128 to ON only for expansion module on a ZFR/ZFR Pro Series Wireless Field Bus application. For all hard-wired SA and FC bus applications, ensure that switch 128 is set to OFF.
    Note: Do not connect an expansion module with switch 128 set to ON to an active (hard-wired) SA or FC bus. When an expansion module with switch 128 set to 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 expansion module is disconnected or switch 128 is set to OFF.
  4. 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.
  5. Write each expansion module's device address on the white label below the DIP switch block on the expansion module's cover.