The HIMA EABT3 B9302 (part number 997009302) is an I/O Subrack Assembly Kit for the HIQuad (H41q/H51q) safety systems.1

While the B5233-1 (which we discussed earlier) is the Central rack housing the CPUs, the B9302 is the Expansion rack used to house the actual input and output modules that interface with your field devices.

Kit Components

When you order the B9302 assembly, it typically comes pre-configured with:

1 x K 1406 I/O Subrack: A 19-inch, 4 HU (Height Unit) chassis.2

1 x F 7553 Coupling Module: Pre-installed in Slot 17.3 This module manages the connection between this I/O rack and the Central CPU rack.

1 x BV 7032 Flat Cable:4 Used to daisy-chain the I/O bus. The suffix (e.g., B9302-0.5) indicates the cable length in meters.5

Slots 1–16: These are reserved for your specific I/O modules (e.g., Digital Input F3236. Analog Input F6217).6

Slots 18–21: Reserved for optional F 7133 Power Distribution modules (up to 4 can be added).7

Technical Specifications

Maintenance & Diagnostics: The F 7553 Module

Since the F 7553 Coupling Module is the heart of this specific kit, keep an eye on its front panel LEDs:

WD (Green): Indicates the Watchdog signal is present.8 If this is off, the rack’s outputs will likely fail to a safe state (de-energized).

SEL (Yellow): Flashes when the Central Module is actively communicating with (selecting) this specific I/O rack.

WD Switch: There is a shrouded slide switch on the front. This allows you to manually disable the Watchdog signal for this rack during maintenance without tripping the entire system’s Emergency Off (but use this with extreme caution).9

Common Spare Parts for this Rack

F 7133 (981713302): 4-fold power distribution module with fuses.10

F 7546: Bus termination module (required if this is the last rack in the I/O chain).