You can implement a custom TIdIOHandler-derived class that accesses a serial port instead of a socket. >Does anyone has a tip for a Delphi ModBus driver which supports >synchronous I/O? Indy (which ships with Delphi) uses synchronous I/O for its communications. supports blocking (synchronous) I/O operations. Bohren And Der Club Of Gore Sunset Mission Rar. This works well, nothing wrong >with ModLink, but for this new project I want to use a driver which > Micom S1 V2 Data Model. Cock wrote: >Have done this before using ModLink.