Description
Product Core Brief
- Model: PM556-TP-ETH
- Order Code: 1SAP121200R0071 / 3ABD00034186
- Brand: ABB
- Series: AC500-eCo Compact PLC
- Core Function: Compact CPU module with integrated Ethernet for machine control, packaging, conveying, and small process stations
- Product Type: PLC CPU Module / Compact Controller
- Key Specs: 512 kB program memory | 8 DI / 6 DO transistor | 24 V DC | Ethernet RJ45 + RS485 COM1 | Modbus TCP / Modbus RTU / CS31 | IEC 61131-3 programming
- Condition: New Original / New Surplus (verify per listing)
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | |
| Order Code | 1SAP121200R0071 / 3ABD00034186 |
| Product Type | AC500-eCo CPU Module |
| Program Memory | 512 kB Flash EPROM |
| Data Memory | 64 kB (%MB area) |
| Integrated DI | 8 × 24 V DC, sink/source compatible |
| Integrated DO | 6 × 24 V DC transistor, 0.5 A per point, 2 A per group |
| Supply Voltage | 24 V DC ±10%, typical 70 mA, max 3.3 W |
| Communication | 1× RJ45 Ethernet + 1× RS485 COM1; optional COM2 |
| Protocols | Modbus TCP, HTTP, FTP, SNTP, DHCP; Modbus RTU/ASCII, CS31 master |
| Extension | Up to 10 local I/O modules (S500 / S500-eCo compatible) |
| Mounting | 35 mm DIN rail, IP20, approx. 45 × 100 × 120 mm |
| Operating Temp | 0 °C to 60 °C horizontal installation |
| Engineering Tool | Automation Builder / AC500 Control Builder (IEC 61131-3) |
Note: PM556-TP-ETH is an AC500-eCo CPU, not an AC500 flagship CPU, Advant OCS module, or AC800M controller. Some listings may omit the full order code; always confirm 1SAP121200R0071 against the nameplate before replacement.
Product Introduction
The ABB PM556-TP-ETH is a compact CPU module from the AC500-eCo family, designed for small to medium automation tasks where space, cost, and Ethernet connectivity matter. It integrates 8 digital inputs and 6 transistor digital outputs, plus an Ethernet port and an RS485 serial port, making it suitable for standalone machine control or as a field controller connected to an HMI, SCADA, or higher-level PLC system.
With 512 kB of program memory and bit instruction execution around 0.08 μs, PM556-TP-ETH handles logic sequencing, interlocking, counting, timing, and basic process control tasks efficiently. The built-in Ethernet interface supports Modbus TCP, HTTP, FTP, and DHCP, while the RS485 COM1 port can be configured for Modbus RTU/ASCII or CS31 master communication. An optional COM2 module can further extend serial connectivity.
For system integrators and MRO buyers, this CPU is typically replaced during machine upgrades, panel rebuilds, spare-part replenishment, or when an existing AC500-eCo station requires a verified replacement unit. Because AC500-eCo shares the same software environment and I/O ecosystem with the broader AC500 platform, it can be extended with additional S500/S500-eCo I/O modules and integrated into Modbus or CS31 networks without extra communication hardware.
QA & Testing SOP
- Nameplate verification — Confirm PM556-TP-ETH and order code 1SAP121200R0071.
- Visual inspection — Check housing, DIN-rail clip, terminal blocks, Ethernet/RS485 ports, and LED indicators.
- Power-up test — Apply 24 V DC and verify RUN/STOP/ERROR LED behavior.
- Ethernet test — Assign an IP address and verify Modbus TCP or HTTP access.
- I/O test — Force DI/DO points to confirm input detection and transistor output switching.
- Program download test — Connect via Automation Builder / Control Builder and verify online access.
- Communication test — Validate Modbus RTU or CS31 communication if connected to remote devices.
All units ship in anti-static packaging. A test log can be provided on request when bench testing is available.
Installation Pitfalls & Guide
Confirm it is AC500-eCo, not AC500 flagship. PM556-TP-ETH belongs to the AC500-eCo compact family. It is not interchangeable with PM571, PM581, PM591, or AC800M CPUs.
Check the order code carefully. The correct factory code is 1SAP121200R0071. Some suppliers list only “PM556-TP-ETH” without the full code.
Verify supply voltage. This CPU requires 24 V DC. Do not connect 100–240 V AC; AC-supply variants exist only for other models such as PM554-RP-AC.
Terminals may be sold separately. PM556-TP-ETH uses pluggable terminals; some shipments do not include terminal blocks. Confirm before installation.
Set COM1 mode correctly. The RS485 port must be configured as Modbus RTU, Modbus ASCII, CS31 master, or free protocol depending on the connected device.
Respect DO current limits. Each transistor output supports up to 0.5 A, and each group up to 2 A. Inductive loads should use flyback diodes or surge suppression.
Replacement steps:
- Back up the existing PLC program and note IP address, COM settings, and I/O mapping.
- Power off the 24 V supply.
- Remove the old CPU and label terminal wiring.
- Install the new PM556-TP-ETH on the DIN rail.
- Reconnect terminals and verify Ethernet/RS485 cabling.
- Power up, download the program, and validate I/O and communication.
Technical FAQ
What is the order code for PM556-TP-ETH? The typical factory order code is 1SAP121200R0071, also referenced as 3ABD00034186.
How is PM556-TP-ETH different from PM554-TP-ETH? PM556-TP-ETH has 512 kB program memory, while PM554-TP-ETH typically has 128 kB. Both provide 8 DI / 6 DO transistor outputs and integrated Ethernet.
Can it communicate with HMIs and SCADA? Yes. The Ethernet port supports Modbus TCP, HTTP, and FTP, which are commonly used for HMI, SCADA, and data collection.
Does it support analog I/O? The CPU itself has no integrated analog channels, but analog modules can be added via the local S500/S500-eCo I/O expansion bus.
Which software is used for programming? ABB Automation Builder / AC500 Control Builder, supporting IL, FBD, LD, SFC, and ST per IEC 61131-3.
Do you stock single units? Yes. Single units are available for MRO replacement; project quantities and matched I/O kits can be quoted on request.
