modbus

What problem does it solve?

Modbus register maps often take significant effort to convert into working EPICS IOCs, because you must correctly wire communication ports, protocol interposing, Modbus port drivers, and matching database records.

Core Features & Use Cases

• End-to-end Modbus IOC configuration: translate device register maps into asyn IP/serial port setup, modbus interpose configuration, and Modbus port driver creation.
• Accurate function-code and datatype mapping: select the correct Modbus function code (FC1/2/3/4/5/6/15/16/23) and match it to EPICS record templates and data types.
• Database templates and substitution generation: choose the right record templates (bit/word/analog/string/arrays) and produce substitution entries with correct PORT and OFFSET semantics.
• Use Case: You have a PLC with mixed discrete inputs, holding registers, and float sensor values; use this Skill to produce the required st.cmd logic plus templates-driven substitution files that correctly poll and write those registers over TCP, UDP, RTU, or ASCII.

Quick Start

Configure an EPICS Modbus IOC by choosing the correct connection type (TCP/UDP/RTU/ASCII), creating modbus ports for each contiguous address range and function code, and then generating a substitution file that instantiates the appropriate database templates using the provided register offsets and data types.