Product Core Brief
- Model: PM556-TP-ETH
- Order Number: 1SAP121200R0071
- Brand: ABB
- Series: AC500-eCo compact PLC CPU
- Core Function: Executes control logic and manages local I/O and Ethernet/serial communication for small and medium automation systems.
- Product Type: PLC CPU module
- Key Specs: 512 kB program memory | 8 DI / 6 DO transistor | Ethernet + RS485 | 24 V DC | up to 10 local I/O modules
- Condition: New Surplus / New Original (subject to available stock)
Product Introduction
The ABB is a compact AC500-eCo CPU module designed for machine control, process automation, and distributed I/O applications. It integrates 8 digital inputs, 6 transistor digital outputs, one RJ45 Ethernet port, and one RS485 serial port, making it suitable for systems that need built-in communication without adding extra communication cards.
With 512 kB Flash program memory and a bit instruction time of about 0.08 μs, the PM556-TP-ETH handles more complex logic than entry-level AC500-eCo CPUs. It supports IEC 61131-3 programming languages and can be engineered in ABB Automation Builder. The module supports local expansion with up to 10 S500 / S500-eCo I/O modules, and offers built-in Web server, FTP, Modbus TCP, Modbus RTU/ASCII, CS31 master, and SMTP email alarm functions.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Model | |
| Order Number | 1SAP121200R0071 |
| Product Type | AC500-eCo PLC CPU module |
| Program Memory | 512 kB Flash EPROM |
| Data Memory | 64 kB (%MB area) |
| Bit Instruction Time | 0.08 μs |
| Integrated Digital Inputs | 8 × 24 V DC, sink/source |
| Integrated Digital Outputs | 6 × 24 V DC transistor, 0.5 A per point |
| Communication | 1× Ethernet RJ45, 1× RS485 COM1, optional COM2 |
| Supported Protocols | Modbus TCP, Modbus RTU/ASCII, CS31, HTTP, FTP, SNTP, DHCP, SMTP |
| Local I/O Expansion | Up to 10 modules, max. 335 local I/O channels |
| Supply Voltage | 24 V DC ±10% |
| Power Consumption | Max. 3.3 W, typical 70 mA |
| Mounting | 35 mm DIN rail |
| Protection Rating | IP20 |
| Operating Temperature | 0 °C to 60 °C horizontal installation |
| Programming | IEC 61131-3 via Automation Builder |
Note: Exact firmware, option slot configuration, and COM2 availability should be confirmed from the physical nameplate and OEM manual.
Quality Control Process
- Verify 1SAP121200R0071 on the nameplate.
- Inspect the housing, DIN-rail clip, terminal blocks, Ethernet port, and RS485 connector.
- Apply 24 V DC and check LED indicators and LCD display status.
- Confirm Ethernet and RS485 communication with a PC or HMI.
- Test integrated DI/DO channels and verify local I/O bus operation before dispatch.
Replacement Pitfall Guide
- Don’t confuse it with PM554-TP-ETH. PM554 has smaller program memory; PM556 is the 512 kB version and better suits larger programs.
- Check the Ethernet variant. PM556-TP without “ETH” may not have the same built-in Ethernet capability.
- Verify I/O type. This is a transistor output CPU; do not replace it with a relay-output model unless the load circuit is confirmed.
- Confirm local expansion limits. The module supports up to 10 local I/O modules; exceeding this requires remote I/O or a higher-end AC500 CPU.
- Back up the program. Before replacement, download and save the project via Automation Builder or SD card.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| ABB 1SAP121200R0071 | ABB | Direct | Match order number and firmware. |
| ABB | ABB PM554-TP-ETH | Needs Adaptation | Smaller memory; may not support existing program. |
| ABB | ABB PM566-TP-ETH | Needs Adaptation | Different I/O layout and analog channels. |
| ABB | AC500 V3 CPU | Not Recommended | Requires project migration and hardware reconfiguration. |
Benchmark notes:
- Program memory: 512 kB Flash, suitable for complex AC500-eCo applications.
- Integrated I/O: 8 DI / 6 DO transistor, 24 V DC.
- Communication: Ethernet + RS485 with Modbus TCP/RTU, CS31, Web/FTP/SMTP.
- Expansion: Up to 10 local S500 / S500-eCo I/O modules.
