Com'X200 with PM556x meters

[LaurentCoene]

When it comes to connecting meters, my first thought is going to use the modbus serial port. (as long as the meter is next to the gateway). Even though the solution is proven and works great, there are always people inverting the + and -, or doing some silly errors. As the number of meters increase, the possibilities of errors grows too. And now, comes the new PM556x meter, which has 2 ethernet ports (one with an IP and the other one that works as a switch in order to connect more meters in serie).

An interesting way to connect the meters would be to simply use small ethernet cables and use modbus TCP. That way you completely remove the possibility of error during the installation. Basically you go Com'X200 <--> PM <--> PM <--> PM.

Now I can see the questions coming:

1) What if the PM in the middle dies? Will I still be able to communicate with the last one. If we are using Modbus, the answer is Yes, but if we are using the switch of the meter, not really sure.

2) Will I have to set a static IP on each meter for this to work? Yes, but you would have to define the Modbus ID, so it's about the same amount of work.

3) Could you use DHCP on the meter and then have the Com'X200 do an auto-detect? Unfortunately not today, the Com'X200 will require for you to enter an IP (not a range) - not even the range on its allocated IP table.

4) Could you assign the IP remotely through the DHCP server recognizing the MAC address of the meter? Even though most DHCP servers have this functionality, the Com'X200 does not have the interface to support it. Even though, since the underlying OS is linux, I'm sure it could support this in the long run.

Would you guys have other questions? As soon as I can put my hands on a couple of these babies, I promise we'll try and test some of these ideas.