RS232 using EVKs

The Adesto Technology /Semitech SM240o is a multi-standard powerline communications modem that can be easily configured for industrial and metering applications.

RS-485 is a common protocol used in electricity meters and in industrial control and instrumentation applications.

The serial-to-PLC adapter is a simple way to extend/replace existing serial connections with  PLC without having to change any other software or hardware components. The adapter utilises passthrough firmware that conveys bytes from a serial port to PLC and vice versa.

RS232 using EVKs

There are two passthrough variants:

ASCII passthrough: copies all ASCII characters, which are received on the UART, verbatim to the PLC line, and conversely, forwards all ASCII characters received from the PLC line verbatim to the UART. The transmission to the power line in “ASCII passthrough” is triggered by reception of a special ASCII character, normally “End of Line” or “Carriage Return”, and can be changed on request. The configuration in “ASCII passthrough” can be changed using AT commands.

TP passthrough: is a variant of passthrough firmware, which forwards all bytes from the UART (not necessarily ASCII) to the PLC line, and, conversely, forwards all bytes received from the PLC line verbatim to the UART. The transmission to the power line in “TP passthrough” is triggered by timeout. Hence the name – Timeout-based Packetization. The acronym can also can be expanded as TransParent, as this variant requires practically no effort from the user. The limitation of this mode is that there is no way to change the configuration.

Note: The “ASCII passthrough” and the “TP passthrough” firmware does not support the protocol we use for our GUI which is   available on most other firmware packages. Consequently, cannot be used to communicate with the Serial-to-PLC Adapter. Use serial terminal applications instead.

The SM2400 PLC device with “ASCII passthrough” or “TP passthrough” is ideal for industrial control applications to replace or extend RS232 or RS485 connection without having to modify other parts of the systems or any of the software protocols.

1.           Features

  • Replacement of RS232 cable with DC or AC power line
  • Replacement of RS485 multidrop network with DC or AC power line
  • Using the powerline saves the cost of installing dedicated communications cables
  • Supports Modbus protocol
  • Operational band: FCC (Cenelec-B/C version available)
  • PLC PHY: OFDM (G3 FCC) or XXR (when additional robustness is required)
  • Effective PHY data rate up to 300 kbit/s (depending on band used)
  • Serial port interface speed: up to 625kbit/s
  • Packet size: up to 350 characters
  • Seamless PLC transmission with retries to improve robustness
  • Fully transparent mode (TP passthrough), plug and play coming out of the box without the need to do any programming.
  • Serial and PLC configuration parameters are accessible via AT commands (ASCII passthrough)
  • Please email us and we can provide more information

We now are working with Adesto Technology