A communication protocol developed in 1979 by Modicon for use with their Programmable Logic Controller (PLC). It is a free and open protocol that helped get the protocol adopted by many users and devices.
A serial connection, or serial communication, is the process of sending data one bit at a time over a connection or communication channel in a sequence.
10BaseT is a twisted-pair cable that is used for LAN and can achieve speeds of up 10Mbps.
A Remote Telemetry Unit (RTU) is a device created for monitoring and reporting events that occurs at a remote site. The typical events that will be monitored are temperature, humidity, and voltage levels. Almost anything can be monitored with an RTU. Information regarding these events are collected by the RTU and then sent out to a master station like the T/Mon.
An Intelligent Electronic Device (IED) is a microprocessor-based controller that has advanced local control intelligence.
TCP/IP is used as the transport protocol of the Internet and is made up of two different protocol layers. The first layer, the transport layer, is also called the Transmission Control Protocol (TCP). It is used to break up a message or file into smaller pieces of data called packets, then send them over the Internet.
It is also responsible for rearranging the packets when it receives them. The second layer is the Internet layer. It is called the Internet Protocol (IP) and it is used for addressing the packets so that the packets will get to the correct destination.
If you work in telecom, you probably have trouble with any remote RS485 Modbus equipment. The world has shifted more and more to IP, T1, fiber, and other modern transport standards. Dedicated serial lines are tough (and expensive) to maintain. Wouldn't it be nice to route serial traffic over IP? Then you could keep you old-but-still-functional Modbus gear but abandon the aging serial transport.
One excellent new solution to this problem is a remote Modbus-to-SNMP mediator. This is a fairly simple box that takes in serial Modbus (RS-232 or RS-485) and converts the Modbus message to standard SNMP traps. These can be received by your SNMP manager. Because the mediator box is modern, you benefit from recent innovations like SNMPv3.
Unlike earlier versions of SNMP, SNMPv3 is secured with encryption. For many organizations, this level of security is needed whenever data will be sent via IP.
If serial transport isn't your problem, but you still want to integrate Modbus into your SNMP umbrella, you can take a different route. This involves using a Modbus mediating master station to convert inbound Modbus to SNMP. This single stream of usable SNMP traps can be easily sent to your preferred SNMP manager. This master-station solution will generally be much less expensive than installing individual mediation devices at each of your remote sites.
If you work with any kind of legacy equipment, including serial Modbus, you need very specialized gear to make it work in today's networks. That's where your choice of manufacturer comes in. Some just sell commodities, if you need a very unique solution, you're out of luck.
What you need to get a custom solution is a manufacturer who can take a proven design and adjust the design to fit your needs. Look for a company that does its own engineering and manufacturing. They need in-house teams in those areas to be responsive to your special requests. Otherwise, they'll have a really hard time meeting your specs without an insane minimum order.
A company that farms out everything except for their "core competency" simply can't react with the speed that an integrated company can. You need a manufacturer whose core competency is being flexible and giving you the exact solution you need.