ABB PM858K02 CPU Redundant Controller 33MHz 16MB

ABB PM858K02 Redundant Controller

Product Introduction
The ABB PM858K02 delivers reliable control for demanding industrial environments. This redundant controller package includes two separate PM858 CPUs, ensuring seamless switchover within 10 ms. Each CPU board features a 33 MHz processor, 16 MB of RAM, and a real-time clock. You also get LED indicators, an INIT push button, and a CompactFlash interface. The base plate (TP830) provides two RJ45 Ethernet ports for the Control Network, plus two serial ports (COM3 RS-232C with modem control, COM4 isolated for configuration tools). This hardware supports CPU, CEX-Bus, communication interfaces, and S800 I/O redundancy. Consequently, system uptime improves significantly.

Technical Specifications of ABB PM858K02

The PM858K02 includes a MPC866 processor with 33 MHz clock frequency. For application memory, it offers 16 MB total RAM, out of which 7.147 MB is available for your control logic. Additionally, flash PROM provides 4 MB of firmware storage. The controller runs on 24 V DC (range 19.2-30 V DC). Typical power consumption is 210 mA, with a maximum of 360 mA. Therefore, power dissipation stays at 5.1 W typical (8.6 W max).

Regarding performance, the system handles 1000 boolean operations in only 0.36 ms. Each controller supports up to 32 applications, 64 programs per application, and 128 diagrams per application. Moreover, you can define 32 tasks with cycle times down to 1 ms. The real-time clock stability reaches 100 ppm (approximately 1 hour/year). Clock synchronization across AC 800M controllers uses the CNCP protocol with 1 ms accuracy.

For connectivity, the PM858 CPU provides two Ethernet channels (10 Mbit/s, RJ-45) using MMS and IAC protocols. The recommended backbone is 100 Mbit/s switched Ethernet. On the CEX bus, you can connect up to 12 communication modules. The Modulebus supports either one electrical plus seven optical I/O clusters for non-redundant setups, or seven optical clusters for redundant CPUs. Maximum I/O capacity reaches 96 modules (single) or 84 modules (redundant).

Environmental and Mechanical Parameters

The ABB PM858K02 operates between +5 and +55 °C. Storage temperature ranges from -40 to +70 °C. Relative humidity stays between 5% and 95% non-condensing. Protection class is IP20 according to EN 60529, so no additional enclosure is required for most indoor installations. Vibration resistance meets IEC/EN 61131-2 standards: 0.0375 mm amplitude from 10 to 50 Hz, and 0.5 g acceleration from 50 to 150 Hz. Furthermore, the unit holds marine certificates (DNV-GL) and hazardous location approval (cULus Class 1, Zone 2, AEx nA IIC T4). It is also ISA Secure certified and fully RoHS compliant.

Dimensions are as follows: width 119 mm, height 186 mm, depth 135 mm. The K02 version weighs 2700 grams including both base plates. Noise emission is below 55 dB(A). Moreover, the controller includes a built-in backup lithium battery (3.6 V) for memory retention. Redundant power supply status input is also available.

Frequently Asked Questions (FAQ)

1. Is the PM858K02 compatible with older System 800xA versions?
No, this controller works only with System 800xA 6.0.2, Compact Control Builder 6.0.0-1, and newer releases. Please check the Product Update notes before ordering.

2. What happens if one CPU fails in a redundant setup?
The system switches over automatically within 10 ms maximum. The second PM858 CPU continues normal operation without interruption. Therefore, your process remains stable.

3. Can I use the COM3 port for standard serial communication?
Yes, COM3 is an RS-232C port with full modem control signals (RTS-CTS). It supports baud rates from 75 to 19,200. However, note that this port is not opto-isolated.

4. How do I find the Ethernet address for my TP830 base plate?
Look for the Ethernet address label attached directly to the TP830 base plate. This unique address provides a hardware identity for each CPU.

5. Does the PM858K02 support PROFIBUS DP communication?
Yes, the controller supports PROFIBUS DP via additional communication modules on the CEX bus. The hardware uses open standards for optimal connectivity.