Issue:
How to configure and use Modbus Slave protocol for PowerLogic P5 relays, including supported modes, function codes, and integration requirements.
Product:
PowerLogic P5 Protection Relay
Environment:
SCADA systems using Modbus RTU (RS-485/fiber) or Modbus TCP/IP (Ethernet)
Industrial networks with multi-protocol support
Configuration tools: eSetup Easergy Pro, Web HMI, front panel
Cause:
Modbus is widely used for simple and reliable data exchange in automation systems. Incorrect configuration of addressing, scaling, or function codes can lead to communication errors, data mismatch, or control failures.
Resolution:
- Protocol Support:
- Modbus RTU: RS-485/fiber, 1200–115200 bps, 2/4-wire
- Modbus TCP/IP: Ethernet, port 502, up to 3 IP addresses/subnets
- Supports up to 8 clients and 4 slave instances
- Configuration:
- Set protocol via COMMUNICATION menu or eSetup Easergy Pro/Web HMI
- Parameters: Slave address (1–247), baud rate, parity, scaling, IP filtering
- Function Codes:
- 03 (Read Holding), 04 (Read Input), 06 (Write Single), 16 (Write Multiple), 23 (Read/Write Multiple), 07 (Read Exception Status), 08 (Diagnostics), 11 (Comm Event Counter), 43/14 (Device ID), 20 (Disturbance file)
- Data Model:
- Extensive register mapping for protection, measurement, control, alarms, events, and settings
- Data types: Bool, Enum, Int16/32/64, UInt16/32/64, float32, string
- Scaling examples: 1.00 s = 100, 50.00 Hz = 5000
- Features:
- Real-time measurements, event logs, disturbance records
- Control commands: Open/Close, Select/Execute, latch release, setting group change
- Clock sync via registers (2504–2507)
- Security:
- No encryption; use VLANs, firewalls, IP whitelisting (CIDR, up to 8 entries)
- Port/protocol enable/disable; sFTP for secure file transfer
- Integration:
- Compatible with SCADA, EvoPact HVX, external AI/DI/DO
- Supports redundancy (PRP, HSR, RSTP)
