Description
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | ABB |
| Model | PM556-TP-ETH |
| Product ID | 1SAP121200R0071 |
| Product Type | AC500-eCo PLC Processor Module |
| PLC Platform | ABB AC500-eCo |
| Power Supply | 24 VDC |
| Program Memory | 512 kB Flash EPROM |
| Digital Inputs | 8 DI |
| Digital Outputs | 6 DO transistor type |
| Output Voltage | 24 VDC |
| Output Current | 0.5 A/channel typical |
| Ethernet Interface | 1 × Industrial Ethernet |
| Serial Interface | 1 × RS485 |
| Serial Protocol Support | Modbus RTU / ASCII, CS31, free protocol (configuration dependent) |
| Option Slots | 2 expansion option slots |
| Communication Bus | AC500 I/O bus |
| Mounting | DIN rail mounting |
| Protection Rating | IP20 |
| Operating Temperature | -25°C to +55°C typical |
| Dimensions | 82 × 135 × 74 mm |
| Weight | Approx. 0.3 kg |
Product Introduction
ABB PM556-TP-ETH Overview
The ABB PM556-TP-ETH is an AC500-eCo PLC processor module designed for compact machine control and industrial automation applications. It combines PLC execution functions with integrated digital I/O, Ethernet communication, and RS485 connectivity, reducing the need for separate controller communication hardware.
The ABB PM556-TP-ETH provides 512 kB program memory, 8 digital inputs, and 6 transistor outputs for applications requiring a small PLC footprint with networking capability. It is commonly maintained in existing AC500-eCo installations where replacing the controller platform would require unnecessary engineering effort. Verify firmware compatibility, I/O expansion configuration, and application backup before replacement.
PM556-TP-ETH
Application Scenarios & Field Pitfalls (The Engineer’s Perspective)
Engineering Pain Point
A machine stops production after a controller failure, and the replacement challenge is not always the hardware itself. The real issue is recovering the original PLC application, communication settings, and field I/O mapping. Compact PLC systems are often installed in machines that have been modified over years, making documentation gaps a major commissioning risk.
The ABB PM556-TP-ETH is typically used when maintaining an existing AC500-eCo control solution where the original logic, wiring, and machine sequence need to remain unchanged.
Typical Applications
- Packaging Equipment – Conveyor control, sensor handling, actuator sequencing, and machine interlocks.
- Material Handling Systems – Motor starters, limit switches, position sensors, and local automation control.
- Water Treatment Equipment – Pump control, valve sequencing, and local monitoring panels.
- OEM Machine Systems – Compact PLC applications requiring Ethernet connectivity and distributed I/O expansion.
Technical Pitfalls to Avoid
- Program Backup Verification
A replacement CPU does not contain the original application logic. Always confirm the PLC project file, firmware version, and communication parameters before shutdown.
- I/O Configuration Differences
The PM556-TP-ETH includes integrated I/O. Verify whether the existing program uses onboard channels or expansion modules. Incorrect channel mapping can cause unexpected machine behavior.
- Communication Parameter Loss
Ethernet and RS485 settings are stored within the PLC project. Record IP addresses, Modbus settings, and connected device parameters before replacement.
Field note: Before removing the old CPU, save the application program, record the RUN/STOP status, photograph wiring terminals, and document connected expansion modules. Small PLC systems often lack redundant documentation.
Related Products
- ABB PM554-TP-ETH
Smaller -eCo CPU variant with Ethernet communication. Suitable for simpler machines requiring less program memory and fewer resources. - ABB PM564-TP-ETH
-eCo CPU with analog I/O capability. Used when applications require integrated analog measurement and control functions. - ABB PM566-TP-ETH
Higher -eCo CPU model with 512 kB memory and expanded processing capability. Selected for larger compact PLC applications. - ABB PM556-TP
Similar CPU platform without integrated Ethernet interface. Used in applications where serial communication is sufficient. - ABB CM574-RS / CM574-RS-ETH Communication Modules
Expansion communication modules used to add additional network interfaces to compatible PLC systems. - ABB S500-eCo I/O Modules
Expansion I/O modules used with -eCo CPUs for additional digital and analog field connections. - ABB PLC Platform
Main PLC family containing -eCo, , and related controller modules for machine and factory automation. - ABB Control Builder Plus
Engineering software environment used for programming and configuring compatible ABB PLC controllers. - ABB PM5012-T-ETH
Migration-related compact PLC CPU option with Ethernet communication for newer -eCo system designs.
