How to connect electrical power meter to a LAN

[Anonimo]

I am looking for the best technical and most economical way to connect my electrical power meter to a LAN using an Ethernet to Serial converter. The power meter we use is the the Acuvim “L” series, more specifically, the “DL” and “KL” series.

These models come with an RS485 MODBUS RTU output, I do not understand clearly the difference between the ATC-1000 Ethernet to Serial converter and ATC-3001.1 port MODBUS Gateway. Can I use for above purpose the ATC-1000 or shall I go to the ATC-3001 ?

I also looking how to read the Acuvim DL and KL through their RS485 MODBUS RTU port converted to a Wireless 802.11b/g. May I use for this purpose the ATC-1000WF or the ATC-2000WF ?

[Sergio Bertana]

All the Ethernet to Serial Converters (and which we distribute also) are able to work in several different ways, usually they are configurable by a web browser. The Wireless to serial converters work in the same way, the ATC-1000WF has a web interface the ATC-2000WF no.

Server:  They accept an TCP/IP connection on a dedicated TCP port (It’s possible to define which) and when a client connect to them all the characters received by this connection are sent to the serial line and vice versa.

Client: You must define to which IP server and TCP port it has to connect, ad when a character is received by the serial line it connects to the server and sends the received character to int and vice versa.

UDP: A TCP connection is made by the UDP protocol and the converter acts as a Client/Server. This is a faster communication way but you must define the IP address of the UDP server and so it’s difficult to use through Internet connection.

All of them have a Virtual COM program that install a serial COM in your PC, so you just open the communication on this port and dialogue with it exactly as a standard COM port. Pay attention: unfortunately the virtual COM software has compatibility problem and the TCP/IP communication introduces some delay that can compromise the modbus communication. The only way to know if your program work well is to test.

[Sergio Bertana]

The ATC-3001 communicates in the same manner but operates a protocol translation. So the equipment connected to the ethernet communicates with the Modbus TCP protocol and the module converts it to Modbus RTU or Ascii to the serial line and vice versa. As you see in this topic unfortunately the converter doesn’t manages the node ID between modbus TCP to RTU/AScii so it’s not possible to create a daisy chain connection on the RS485 serial line.

To conclude this report if you connect to the meters by using a Virtual COM you can use any Ethernet to serial converter, your software uses the modbus RTU protocol over the Virtual COM and it’s possible to have a daisy chain on a RS485 network.

If you want to eliminate the Virtual COM (To avoid any possible compatibility problems) it’s possible connect to the Ethernet to serial converter in TCP mode (Only if your software allows this), but in this case, specially for the SCADA softwares you have to use the Modbus TCP protocol, and so it must be used a Modbus gateway module as ATC-3001 and it’s not possible to have a daisy chain on a RS485 network.

[Sergio Bertana]

Just a remark for people who has experience in PLC programming at a paragonable cost to the Ethernet to serial converter it’s possible to use our SlimLine ARM7 Compact Ethernet with the DataStreamExch (Manual abstract) (See topic with source program), or ModbusTCPGateway (Manual abstract) (See topic with source program) FBs it’s possible to have both the type of converters.

[Anonimo]

Thank you for your answer but I am still in doubt. I would like to know specifically, for my application, to connect my electrical power meter to Ethernet. The Acuvim “L” series, more specifically, the “DL” and “KL” series which come with an RS485 MODBUS RTU output. Can I use for above purpose the ATC-1000 or shall I go to the ATC-3001.1?

[Sergio Bertana]

The answer is in the previous posts if you use the Virtual COM you can use any Ethernet to serial converter (ATC-1000 is the cheapest). For Wireless communication if you use the WiFi you can use any WiFi to serial converter, with a Virtual COM (I suggest the ATC-1000WF).

[Autore]

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