Modbus serial provides a way to connect to various industrial electronic devices such as programmable logic controllers (PLCs), motor controllers, and remote terminal units (RTUs). Many of the data types are named from its use in driving relays: a single-bit physical output is called a coil, and a single-bit physical input is called a discrete input or a contact.
The Freelance controllers AC 700F, AC 800F and AC 900F support Modbus serial with:
- Modbus ASCII (Master / Slave)
- RTU (Master / Slave)
- Telecontrol IEC 60870-5-101