SL100: Communications

The SL100 implements 3 serial communications protocols: Our proprietary SPLatLink, the industry standard ModBus RTU (master or slave), and the "User programmable protocol".

These protocols use the programming (serial) port. This is an RS232 compatible port with a 9-pin connector. This will connect directly to any PC that has an RS232 (COM port), or to any other device that has RS232, given the right cable. The maximum cable length is 5m. You can also use an MB485 adaptor to convert it to RS485, which will allow connections up to hundreds of meters.

User programmable protocol

This refers to the ability of SPLat to be programmed to send and received arbitrary characters. More information.

ModBus RTU Slave

ModBus is the oldest and most widely accepted protocol in automation. This controller supports ModBus RTU slave mode. In the initial implementations the ModBus feature allows message lengths up to the ModBus limit of 255 bytes. This may be reduced in the future as we add new features and have to "take back" some of the memory. In practice a 64-byte message can transfer 57 bytes of data.

More information on ModBus.

ModBus RTU Master

This controller supports ModBus RTU Master mode.

SPLatLink

SPLatLink is our proprietary protocol for communicating with a SPLat controller while it is running your SPLat Program.

SPLatLink is deprecated. We discourage its use in custom applications.