New Original ABB ABB PM 904F 3BDH001002R0001 Freelance AC 900F CPU Module

Product Details

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FAQs

Q1: What is the primary function of the ABB PM 904F?

It is the central processing unit for the Freelance AC 900F DCS. It executes control strategies, manages I/O communication, handles fieldbus integration, and provides the computing platform for process control applications. It supports multitasking with configurable cycle times from 5 ms and up to 1,500 I/O points.

Q2: Does the PM 904F support redundancy?

Yes. It natively supports 1:1 hot-standby redundancy with a switchover time of approximately 500 ms. The backup CPU runs in parallel with the primary, mirroring and updating the database, ensuring continuous operation in critical processes.

Q3: What communication protocols does the PM 904F support?

The module supports Modbus TCP/IP, IEC 60870-5-104 (Ethernet), Modbus RTU/ASCII, IEC 60870-5-101 (serial), and PROFIBUS DP V0/V1 and ABB CAN Bus via optional communication interface modules.

Q4: What is the difference between PM 904F and PM 902F?

The PM 904F is the high-end "Plus" variant with 48 MB controller memory and 4 communication interface slots. The PM 902F is the Standard variant with 24 MB memory. Both share the same 800 MHz processor and 4 Ethernet interfaces, but the PM 904F supports more I/O points and larger applications.

Q5: What display and battery options are available?

The TD 951F Display Unit provides local status and diagnostic information. The TA 951F Lithium Battery backs up SRAM contents and the real-time clock, providing buffering for >2 years at +40°C (after battery low warning: 14 days). Both are ordered separately.