Honeywell 2MLR-CPUH/F MasterLogic CPU Module

The Honeywell 2MLR-CPUH/F is a non-redundant CPU module engineered for high-performance control within the MasterLogic-200 PLC system. It features a 10 MB program memory, 16 MB flash memory, and supports up to 23,808 local I/O points across 31 bases and 372 slots, delivering high-speed execution for complex batch and continuous industrial processes.

Program Execution and Instruction Processing

The CPU executes basic LD instructions at 0.042 us per step and MOV instructions at 0.126 us per step. For floating-point math, single-precision addition/subtraction completes in 0.602 us, multiplication in 1.106 us, and division in 1.134 us, while double-precision operations require 1.078 us, 2.394 us, and 2.66 us respectively.

Program control methods include cyclic scanning, time-driven interrupts, and internal memory interrupts. I/O refresh supports both scan-synchronous batch processing and immediate direct instruction execution. Programming supports Ladder Diagram (LD), Sequential Function Chart (SFC), Structured Text (ST), and Instruction List (IL) in view-only mode.

Memory Allocation and System Capacity

System memory includes 512 KB of symbolic variable memory (up to 256 KB retain settable) and 256 KB of direct variable memory (%MW0 to %MW131071 with up to 128 KB retain settable). Additional fixed memory space includes 128 KB for file registers (%RW), 16 KB for input image tables (%IW), 16 KB for output image tables (%QW), and dedicated system flags for PID loop processing, high-speed links, and P2P communications.

The module manages up to 128,000 network or remote I/O points using Smart I/O modules. Maximum rack extension distances reach 100 m using UTP copper cabling and up to 2 km with fiber-optic links.

Communication and Hardware Interfaces

The CPU features built-in communication interfaces, including one RS-232C serial port supporting Modbus slave protocol and one USB port (12 Mbps) for programming and configuration. Additional network connectivity can be expanded using rack-mounted serial or Ethernet modules.

Operating on a 960 mA backplane current draw, the processor performs comprehensive self-diagnostics including watchdog timing, memory verification, I/O monitoring, battery status, and power sags. In failover conditions, switchover time completes in less than 50 ms.

Technical Specifications

Frequently Asked Questions

Q: What is the maximum local I/O capacity supported by the 2MLR-CPUH/F CPU module?

A: It supports up to 23,808 local I/O points when using 64-channel discrete I/O modules distributed across up to 31 expansion bases and 372 slots.

Q: Which communication protocols and interfaces are built directly into the module?

A: The CPU includes a 12 Mbps USB port for configuration and an RS-232C port that natively supports Modbus slave protocol.

Q: How does the module handle retain data during a power failure?

A: Retain data regions for symbolic and direct variable memory are retained based on parameter configuration using battery-backed basic setup parameters.