FOXBORO FBM240 P0917GZ 8 channel output Fieldbus Module
FBM240 (Part No. P0917GZ) is a redundant 8-channel discrete output Fieldbus Module (FBM) with readback function for Foxboro I/A‑Series. It belongs to the Compact200 series I/O subsystem and supports single-module operation or dual-module redundant configuration. It is mainly used for switching relay output control in DCS systems, with relay contact status readback diagnosis capability. It is widely applied in industrial process control scenarios with high reliability requirements such as chemical and power industries.
Product Overview
FBM240 is equipped with 8-channel discrete relay output channels + 8-channel contact voltage readback input channels, and each channel is electrically isolated from each other. Under redundant configuration, a pair of FBM240 modules realize FBM-level redundancy. The two modules share one set of terminal assembly TA. The two modules perform independent output control and independent collection of readback signals. When one module fails, the intact module can continue to drive field output without interrupting the field control signal. Cooperate with the redundant contact output function block in the control software to complete output status verification.
Firmware version requirement: Firmware version 1.40N or above is required to realize complete fail-safe and new terminal assembly functions.
Main Function Features
Output contact readback diagnosis: 8 readback input channels monitor the voltage at both ends of relay contacts. When the actual contact status is inconsistent with the output command status, mark the channel as BAD fault; real-time monitoring of abnormal output status to quickly locate faults of field loops and relays.
Flexible operating modes: Single module / dual redundant module
Redundant configuration: Two FBM240 modules are installed in adjacent odd and even slots of the base, matched with P0927BM redundant adapter. Field wiring is uniformly connected to the same terminal assembly TA. The faulty module marks channel faults, and the normal module takes over the output. The faulty module can be replaced online during maintenance without disconnecting field wiring, power supply and communication cables, and no disturbance to field signals.
Single module configuration: Independently complete 8-channel DO output and readback diagnosis directly.
Configurable Fail‑Safe: The failback value (0 or 1) can be set separately for the 8 output channels;
Mask option: specify which channels maintain the current status and which channels switch to the failback value;
Fieldbus fail-safe delay: set the timeout period for the module waiting for controller communication;
Under redundant mode, the output can be forced to zero when the module is offline for maintenance to avoid interfering with the online working module.
Rich configurable logic functions: Support input filter debounce (0/4/8/16/32ms optional); support continuous output or pulse instantaneous output, and pulse output interval can be configured under pulse mode.
Output capability (with different terminal assembly TA): FBM240 itself does not come with relays. Relays and external power wiring are all implemented on the DIN rail mounted terminal assembly TA. It supports local installation or remote installation up to 30 meters away. The module base and TA are connected through a 37-pin D-Sub cable. Two cable materials are available: polyurethane and LSZH low smoke zero halogen.
Terminal Assembly Model Specification Parameters
| Part No. | Type & Specification |
| P0917YF | 10A relay; 80‑120VAC@10A / 80‑125VDC@5A |
| P0917HU | 5A relay; 80‑120VAC@5A |
| P0926SZ | 5A relay; 15‑30VDC@5A |
| P0916AR | Passive 2A fused output; 15‑60VDC, with voltage monitoring input |
All relays are normally open single-pole single-throw SPST‑NO; relay electrical life: 100,000 operations under rated resistive load, 5 million operations at no load.
Communication and Installation
- Fieldbus communication: Connect to FCM fieldbus communication module or FCP field control processor, adopt 2Mbps redundant module fieldbus; dual-link bus redundancy. If one link fails, the module automatically switches to the normal link to maintain communication.
- Base installation: The module is installed on the modular base backplane; the backplane supports DIN rail installation or 19-inch rack installation; one backplane can accommodate up to 8 FBM modules; redundant modules must occupy adjacent odd and even numbered slots (1&2, 3&4, 5&6, 7&8).
- Power consumption: Module power supply: 24VDC (+5%/-10%); maximum total power consumption of a pair of redundant modules is 5W; power consumption of different TA ranges from 7.6W~15.2W.
Electrical Isolation and Environmental Specifications
- Channel isolation: Each channel is isolated. Channel-to-channel and channel-to-ground can withstand 600VAC for 1 minute withstand voltage; under relay TA mode, input and output are isolated as a whole pair.
- Environmental conditions: Operating temperature: ‑20℃ ~ +70℃; storage temperature ‑40℃~+70℃
- Humidity: 5‑95% RH, non-condensing; maximum working altitude 3000m
- Environmental class: meet ISA S71.04 G3 harsh industrial environment; vibration resistance 7.5m/s² (0.75g) 5‑500Hz.
- Certifications: UL/UL-C explosion-proof certification (Class I Div2 T4), ATEX Zone2 (EEx nA IIC T4); complete industrial EMC electromagnetic compatibility (ESD, electrical fast transient, surge, RF immunity), meet Class A radiated emission. Modules and TA do not require calibration after factory delivery.
Physical Dimensions & Weight
FBM240 module: Approx. 284g; dimensions 102 (H)×45 (W)×104 (D) mm (hanging ear included height 114mm)
TA terminal assembly: 5A spec approx. 454g, 10A spec approx. 908g, 2A passive type approx. 363g; compatible with DIN rail 32/35mm installation.
Application Scenarios
- DCS system solenoid valves, contactors, motor start-stop and other relay switching output;
- Readback verification for output loop to detect relay adhesion and wire breakage;
- High-reliability process units requiring redundant IO and online hot maintenance;
- Mixed AC / DC relay output working conditions.
Note: When driving inductive loads, protective diodes or MOV varistors need to be connected in parallel at both ends of the load to suppress back EMF.
FAQ
Q1: What is FBM240 module?
A: FBM240 (P0917GZ) is Foxboro I/A‑Series 8-channel discrete output fieldbus module with readback. It supports single module / dual redundant module configuration for switching DO output and has relay contact readback diagnosis function. It must be used with the corresponding TA terminal assembly.
Q2: What are the hardware requirements for redundant configuration?
A: Two FBM240 modules are installed in adjacent odd and even slots of the base (1&2, 3&4, 5&6, 7&8); redundant adapter P0927BM is required; two modules share one TA terminal assembly; firmware version ≥1.40N; single terminal cable is led out through redundant adapter to connect TA.
Q3: Can the module be hot-swapped online? Will it affect field output?
A: Under redundant configuration, the faulty module can be directly pulled and replaced without disconnecting field wiring, power supply and communication cables. The intact module continues to drive field output and will not disturb field signals. Removing the module under single module mode will cause output failure.
Q4: What is the function of Readback?
A: 8 readback input channels monitor the voltage at both ends of relay contacts. When the actual contact status is inconsistent with the issued output command, mark the corresponding channel as BAD, which is used to diagnose relay adhesion, loop disconnection and field faults.
Note: When FBM240 output is off, the readback circuit will still flow tiny current through the loop, which is normal.
Q5: What types of TA terminal assemblies are available and how to select?
| Part No. | Type & Specification |
| P0917YF | 10A relay TA, 80‑120VAC@10A / 80‑125VDC@5A |
| P0917HU | 5A relay TA, 80‑120VAC@5A |
| P0926SZ | 5A relay TA, 15‑30VDC@5A |
| P0916AR | Passive 2A fused TA, 15‑60VDC, with voltage monitoring input |
A: FBM240 module body has no relays, all relays are integrated in TA terminal assembly.
Q6: What conditions are required for Fail‑Safe function?
A: Firmware version 1.40N or above; configurable per-channel failback value 0/1, mask, bus communication fault delay; redundant configuration supports forced zero output during module offline maintenance to avoid interfering with online modules.
Q7: What is the communication bus? What is the maximum TA cable distance?
A: Adopt 2Mbps redundant module fieldbus, connect to FCP/FCM controller; maximum length of terminal connection cable is 30m, polyurethane / LSZH low smoke zero halogen cables are available.
Q8: Does inductive load wiring need extra processing?
A: When driving inductive loads (coils, contactors), protective diodes or MOV varistors must be connected in parallel at both ends of the load to suppress reverse induced electromotive force.
Q9: What is the channel isolation withstand voltage?
A: Channel-to-channel and channel-to-ground withstand voltage is 600VAC for 1 minute; under relay TA mode, input and output are isolated as one group.
Q10: Does the module need calibration?
A: FBM240 module and TA terminal assembly do not require calibration after factory delivery.
Q11: Environmental and certification class?
A: Operating temperature -20 ~ +70℃; comply with ISA S71.04 G3 harsh environment; UL Class I Div2 T4, ATEX Zone2 EEx nA IIC T4, industrial Class A EMC.
Q12: Power consumption parameters
A: A pair of redundant FBM240 modules max total power consumption 5W; 5A TA (P0917HU/P0926SZ):7.6W; 10A TA (P0917YF):15.2W.
