HIMA F8621A Coprocessor Module (H41q/H51q)

Overview

The HIMA F8621A coprocessor module is the communication coprocessor of the PES H41q/H51q fail-safe control systems. Per the official HIMA module datasheet, the F 8621A is used in the H41q/H51q from BS41q/51q V6.0-6 (9808) with ELOP II. Although the module is frequently described in the trade as a CPU module, the official HIMA designation is coprocessor module: it carries its own microprocessor and handles the safety-related serial communication of the fail-safe system.

The coprocessor module is built around the HD 64180 microprocessor running at a clock frequency of 10 MHz. It provides 384 kbyte of static memory implemented as CMOS-RAM and EPROM on two ICs, with battery buffering of the RAMs: on the H51q the buffering is provided by the power supply monitoring module F 7131, while on the H41q the buffer batteries are located on the rear PCB of the subrack.

Engineering & Design

The F 8621A provides two RS 485 interfaces in half-duplex mode with galvanic isolation and a dedicated communication processor. Transmission rates are set by software in the range 300, 600, 1200, 2400, 4800, 9600, 19200 and 57600 bps, or the values set on the CU via DIP switches are taken over. A Dual Port RAM provides fast alternating memory access between the coprocessor and the central module.

The module requires a space of 4 SU and operates from 5 V DC with a current consumption of 360 mA. In the central subracks of H51q systems the coprocessor module may only be used in the slots CM1 to CM3. Mixed operation of safety-related communication via the F 8621A and parallel Ethernet communication via the F 8627X is not admissible, as stated in the official datasheet.

Safety Certification and System Context

The F 8621A is a communication coprocessor inside a safety system, so it is worth being precise about what is certified and what is not. HIMA’s own catalogue for the H41q and H51q system families states that these programmable electronic systems are designed for safety-related applications up to requirement class 6 (AK 6) as defined in DIN V 19250, and that the central module and I/O bus carry a TÜV test certificate up to that requirement class. HIMA expresses the certification of this generation in DIN V 19250 requirement-class terms rather than as an IEC 61508 SIL figure, and Seven Star LLC therefore does not quote a SIL number against this module. Where a documented SIL rating is required for a safety instrumented function, take it from the current TÜV certificate issued for your specific H41q or H51q system version and operating-system release, not from a module listing.

It is equally important not to read redundancy into the coprocessor slot. In the H41q/H51q architecture, availability is raised by duplicating the central module, the I/O modules and the I/O bus — the catalogue’s configuration table shows a mono central module for normal availability and redundant central modules for high and very high availability — while up to three coprocessor modules may be installed alongside each central module to expand communication capacity. Adding a second HIMA F8621A therefore adds communication channels; it does not by itself create a redundant safety channel, and the redundant connection to a process control system described below is a specific, engineered arrangement rather than automatic property of fitting two modules.

Key Features

• HIMA F8621A coprocessor module for PES H41q/H51q (with ELOP II, from BS41q/51q V6.0-6)
• Own microprocessor HD 64180, clock frequency 10 MHz
• 384 kbyte static memory: CMOS-RAM and EPROM on two ICs
• Battery buffering of the RAMs (H51q via F 7131; H41q via rear PCB batteries)
• 2 × RS 485 half-duplex interfaces with galvanic isolation
• Transmission rates 300 to 57600 bps, software or DIP switch selectable
• Dual Port RAM for fast access to the central module
• Space 4 SU; operating data 5 V DC / 360 mA

Applications

• Safety-related serial communication with the HIMA F8621A in H41q/H51q systems
• Redundant connection to a process control system (via BV 7040)
• Connection to an ELOP II bus (via cable BV 7046)
• Spare HIMA F8621A module for fail-safe system maintenance

Specifications

Compatibility & Integration

The HIMA F8621A is fitted in the coprocessor slots of the H41q/H51q central subrack (CM1 to CM3 in H51q systems). The redundant connection to a process control system is made via two redundant modules, each with a BV 7040, and the connection to an ELOP II bus is made via cable BV 7046.

When a Profibus-DP communication module F 8628/F 8628X or an Ethernet communication module F 8627/F 8627X is used in addition to the coprocessor module, the software function block HK-COM-3 (from ELOP II V 3.5, BS 41q/51q V 7.08) has to be set up with proper parameterisation, as noted in the official datasheet.

Power, Battery Buffering and Maintenance

The 5 V DC / 360 mA drawn by the coprocessor module comes off the system 5 V rail, which in an H51q central rack is generated from the 24 V DC supply by F 7126 clocked 24 V DC / 5 V DC power supply modules. A central rack takes up to three of these modules switched in parallel; one or two normally supply the whole PES and the third is fitted to raise availability. Their output is watched for undervoltage or failure by the F 7131 power supply monitoring module, and a faulty supply module is reported to the user program through a system variable. Because the coprocessor draws from this shared rail, the 360 mA figure should be added into the rack power budget alongside the central and I/O modules before a further module is fitted to a subrack that is already well loaded.

The same F 7131 module carries the two lithium batteries that buffer the sRAM on the HIMA F8621A. HIMA recommends exchanging these buffer batteries approximately every two and a half years; the F 7131 battery type is CR-1/2 AA-CB, HIMA part number 440000016. The monitoring module can be withdrawn under voltage for the exchange, which raises a system alarm and displays the message BATE, indicating a fault in the external buffering battery, on the central module display. HIMA specifies the desoldering and soldering sequence explicitly — unsolder the positive pole first and then the negative, and when fitting the new cell solder the negative pole first and then the positive — and this order should be followed rather than improvised. During commissioning and routine testing of the central device, the check that applies to the F 8621A is verification of its operating system EPROM, which is the item HIMA lists for this module in its startup and maintenance procedure.

Ordering Information

To order the HIMA F8621A coprocessor module from Seven Star LLC, quote the module number and the quantity required. We confirm availability and delivery to your site in Oman or anywhere in the GCC, and we check the module revision against your H41q/H51q system before dispatch.

Why Seven Star LLC

Seven Star LLC supplies HIMA fail-safe system spares to industrial customers across Oman and the wider GCC region. Every HIMA F8621A coprocessor module we supply is verified against your H41q/H51q system before dispatch, and our team confirms the module revision matches your installation before you order.

FAQ

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