Protocol drivers – a general overview

Introduction

Protocol drivers are the components that interpret the configuration of the tags linked to them, turn that into a data packet in the protocol’s format, send the packet through the communication port, receive the answer, decode it and update the tags’ values — or the reverse path, for writes.

It is the second component to be inserted in a data-acquisition application, right after the communication port and before every tag that will use the protocol driver.

Supported protocols

Protocol class	Protocol	Protocol type	Talks to	Required port class	Supported tags	Tag properties to configure	Notes
TModBusRTUDriver	Modbus RTU	1 protocol component for many stations	Any device supporting Modbus RTU (station addresses 1 to 247)	TSerialPortDriver	TPLCTagNumber TPLCBlock TPLCStruct TPLCString	PLCStation MemReadFunction MemWriteFunction MemAddress TagType	Blocks and structures use, by default, up to 125 registers per read/write block (driver properties HoldingRegsMaxBlockSize/AnalogRegsMaxBlockSize) and up to 2000 bits for digital inputs/outputs (InputsMaxBlockSize/OutputsMaxBlockSize) — all configurable. See Modbus RTU and TCP.
TModBusTCPDriver	Modbus TCP	1 protocol component for 1 or more devices, over the same connection	Any device supporting Modbus TCP	TTCP_UDPPort	TPLCTagNumber TPLCBlock TPLCStruct TPLCString	PLCStation MemReadFunction MemWriteFunction MemAddress TagType	Same block limits as Modbus RTU. See Modbus RTU and TCP.
TWestASCIIDriver	West ASCII	1 protocol component for many stations	West n6100/P6100 controllers	TSerialPortDriver	TPLCTagNumber	PLCStation (1 to 99) MemAddress (0 to 27 — the West parameter)	Every West register is a 32-bit float; the driver ignores the configured `TagType` and always delivers a float — leave it at `pttDefault`. Supports reads and writes. Has its own tag wizard.
TIBoxDriver	Thermo King i-Box	1 protocol component for many stations	Thermo King i-Box refrigeration controllers	TSerialPortDriver	TPLCTagNumber	PLCStation (0 to 255) MemAddress — only registers (PID) 0, 96, 168, 200 to 205 and 247 are accepted	Read-only: the i-Box refuses write commands outright, any attempt returns an error. Values already arrive ready to use (percentage, hours, tenths of a degree) — `TagType` does not change the result.
TISOTCPDriver	Siemens S7 (S7comm) over ISOTCP	1 protocol component for 1 PLC	S7-200 via a CP 243-1 S7-300 / S7-400 (Ethernet) LOGO! 7 and 8 (Ethernet) S7-1200 / S7-1500 (Ethernet, with PUT/GET enabled and non-optimized blocks) S7comm-compatible simulators/gateways (PLCSIM+NetToPLCSim, Snap7 server)	TTCP_UDPPort	TPLCTagNumber TPLCBlock TPLCStruct TPLCString	PLCRack, PLCSlot, PLCStation — on the driver, not on the tag MemReadFunction (area) MemFile_DB (when the area is DB) MemAddress TagType SwapBytes/SwapWords/SwapDWords according to the type	Does not speak the S7-1200/1500 native protocol (S7CommPlus) and does no symbolic addressing — see S7 Protocol over ISOTCP for the full area and type table.
TMelsecTCPDriver	Mitsubishi MC Protocol (3E frame, binary) over TCP	1 protocol component for 1 PLC	Mitsubishi Q, L and iQ-F/iQ-R series with an Ethernet port or a QJ71E71/LJ71E71 module, configured for binary MC Protocol/SLMP	TTCP_UDPPort	TPLCTagNumber TPLCBlock TPLCString	MemReadFunction / MemWriteFunction (device code: M, X, Y, D…) MemAddress (decimal — mind that X/Y are numbered in hexadecimal in the PLC)	Timers, counters, link registers and the SB/DX/DY areas are not supported yet. See Mitsubishi Melsec TCP.
TS7CommPlusDriver	Siemens S7CommPlus	1 protocol component for 1 PLC	S7-1200 and S7-1500 (the native protocol TIA Portal uses, with blocks in optimized access — no need to disable it, unlike ISOTCP)	TTCP_UDPPort	TPLCTagNumber TPLCBlock TPLCString	LongAddress — the tag’s symbolic path in the PLC (e.g. `DB4.Var1`, `MArea.Clock_10Hz`)	Addresses by the tag’s name in the PLC program, not by a memory offset. Dedicated page in preparation.
TLGXDriver	EtherNet/IP (CIP), Rockwell/Allen-Bradley	1 protocol component for 1 PLC	Rockwell/Allen-Bradley Logix-family PLCs (ControlLogix, CompactLogix…) with an EtherNet/IP port	TTCP_UDPPort	TPLCTagNumber TPLCBlock TPLCString	LongAddress — the Logix tag name (e.g. `Motor1.Speed`, `MyString.DATA` for a STRING)	Symbolic addressing, as in TIA Portal/Studio 5000: there is no memory offset to configure. Dedicated page in preparation.