STM-501C
Modbus TCP to Serial RTU/ASCII Gateway

The STM-501C, MODBUS gateway allows the legacy MODBUS RTU/ASCII devices to operate on a MODBUS TCP network. It allows either MODBUS serial master or slave to communicate with MODBUS TCP's slave or master.
Modbus TCP masters to Modbus RTU/ASCII slaves:The STM-501C allows multiple MODBUS TCP masters to communicate with a MODBUS serial network. Since a MODBUS serial network can only handle one query at one time, queries from different masters are pipelined and processed one by one.
Modbus RTU/ASCII master to Modbus TCP slaves: When the STM-501C functions as the MODBUS RTU/ASCII master to MODBUS TCP slave gateway, the STM-501C can connect up to 8 MODBUS TCP slaves. Users can specify a UID range for each MODBUS TCP slave.
Inactive timeout: The STM-501C provides an inactive timeout that allows users to specify a time period to disconnect TCP/IP connection if there is no activity in the network. If the connection does not tear down it would occupy one connection slot and prevent any another connection again.
Configuration tools: User friendly management software provides an easy way to configure the STM-501C. It can search all serial device servers within a local area network independent of its subnet. It can also find a serial device server of a specific IP address over a wide area network. The STM-501C can also be configured by its console port or through telnet connection. The STM-501C provides a web interface for the user to configure it with a web browser.