The HIMA F8650X central module is the core component of the HIMA H51q series programmable electronic systems, designed specifically for applications with the highest level of safety. This module is suitable for H51q MS, H51q HS, and H51q HRS systems, certified by T Ü V, and can reach up to SIL 3 safety integrity level defined by IEC 61508 standard.
The F8650X adopts a dual processor architecture and achieves true fault safety control through hardware comparators. When inconsistencies are detected, the security related watchdog will immediately set the system to a safe state. This module supports RS-485 communication up to 57600 bps and provides a four digit digital display for system diagnostics. This data sheet provides a detailed introduction to the technical specifications, interface definitions, installation and maintenance points of F8650X, as well as its collaborative application with the F8627X communication module.
Core architecture and technical specifications
2.1 Dual processor security architecture
The core security mechanism of F8650X lies in its dual processor design:
Two clock synchronized microprocessors: based on Intel 386EX 32-bit processor, with a clock frequency of 25 MHz, running in parallel.
Independent memory: Each processor is equipped with dedicated Flash EPROM (1 MB) and SRAM (1 MB) to ensure operational independence.
Complementary processing of data/programs: One processor processes real data and programs, while the other processes reverse data and programs, comparing all external accesses in real-time through hardware comparators.
This architecture ensures that any individual processor failure or memory error can be immediately detected, and the system is placed in a defined safe state through a safety watchdog when a failure occurs.
2.2 Safety watchdog
The module is equipped with a safety related watchdog, which has the following characteristics:
24V output: can directly drive external loads.
Load capacity: up to 500 mA, with short-circuit protection.
Fault response: When the comparator detects inconsistent results from the dual processors or other internal faults, the watchdog signal is cut off, triggering the safety shutdown of the associated output module.
2.3 Summary of Technical Specifications
Processor: Intel 386EX, 32-bit, 25 MHz
Program memory: Flash EPROM, 1 MB per processor
Data memory: SRAM, 1 MB per processor
Space requirement: 8 SU (standard unit)
Working voltage: 5 V/2 A
Applicable systems: H51q MS, H51q HS, H51q HRS
Safety level: maximum SIL 3 (IEC 61508)

Interface and Communication
3.1 RS-485 interface
F8650X provides two electrically isolated RS-485 serial interfaces and a 9-pin D-Sub connector. The pin definitions are as follows:
Pin 3 (A/A '): Receive/Send Data A
Pin 5 (C/C '): Data Ground (DGND)
Pin 6 (VP): Positive pole of power supply (+5V)
Pin 8 (B/B '): Receive/Send Data B
Pin 9 (CNTR-B): Control signal B
Important configuration instructions:
Bus station number: For serial interfaces, only 1-31 can be set.
Ethernet extension: When used in conjunction with the F8627X communication module, the bus station number can be extended to 1-99 through switches S1-6/7, etc. However, the number of communication partners within the network is still limited to 64.
Operating system requirements: This enhanced station number setting function requires the operating system version of the central module to be no less than BS41q/51q V7.0-8 (05.31).
3.2 Collaborative application with F8627X communication module
F8650X can be connected to F8627X communication module through backplane bus to achieve Ethernet communication, mainly used for:
Connect programming devices: Implement programming, debugging, and monitoring through the ELOP II TCP protocol.
Ethernet communication: data exchange with communication partners within other networks, such as devices that support safeEthernet or Modbus TCP.
3.3 Special Features
Self learning function: Supported starting from operating system BS41q/51q V7.0-8 (05.31).
ELOP II TCP: Supported starting from the same operating system version.
Regarding the setting of bus station numbers ELOP II TCP、 For more information on operating system and application loading (self-learning), please refer to the F8627X data sheet, H41q/H51q operating system manual, and security manual.
Diagnosis and operation
4.1 Diagnostic Display Screen
The front panel of F8650X is equipped with four digital displays and two LED indicator lights:
Four digit alphanumeric display screen: It can display selectable diagnostic information such as system status and fault codes.
LED indicator lights: CPU LED is used for central module error indication, IO LED is used for testable I/O module error indication.
Toggle switch: used to request detailed error information.
ACK button: Reset error indication. In a fault shutdown state, the ACK function is equivalent to a system restart.
For detailed diagnostic display information and error code list, please refer to the "BS 41q/51q Operating System Functions" document (also included in the ELOP II CD).
4.2 Module insertion and removal operation
Important note: To prevent triggering error signals within the system, module insertion and removal must be performed quickly.