Gambit

Not really as de HMI aren't DHCP servers. If they would be you would get all kinds of trouble as you then could have two of them in your network. So if you haven't setup the HMI with an address for your network. or your not connected to your own network you'll have to setup an ip adres in the same range as your HMI. If you can I would switch it over to a GOT.The program can be converted for the large part and the GOT has a USB connection for easy access.        

looks like the modbus addresses are shown on page 3. Try reading holding reg 2001

You need to know the Modbus adresses of the Cognex not from Mitsubishi. In the pre-defined protocol commands you will read/write from/to Modbus adresses of the cognex. You also specify which Dataregisters will have the date to write or will receive the data 

Ok that's your encoder diameter, But you will need the distance traveled by the system per revolution of the encoder. 

I stand corrected.  @Inntele is correct !!!

Actually they do it's the RTU. https://eu3a.mitsubishielectric.com/fa/en/products/cnt/plcccl/items/smartRTU/local  

That's correct. You can only add 8 special modules. You can add a Analog ADP on the left side if you need more .

Why not use the config tool to check this: http://www.mitsubishielectric.com/fa/products/cnt/plc/ex/select/index.html Choose MELSEC-F 

@Kaare_t means which protocol over RS485. Does it support modbus ?

Well you checked for double coils. but did you also check on list for used devices so you find things like K4M60 which is also M65.

There is a Mitsubishi software removal tool. But I think you\ll have to contact your Mitsubishi dealer.

This is in the GX Works 3 manual appendix 1 http://dl.mitsubishielectric.com/dl/fa/document/manual/plc/sh081215eng/sh081215engr.pdf  

That's just a way you can use names instead of Variables. I would suggest you use this option. Not only does it make more sense to use naming instead of devices. You will also have a list of the devices being used. I always change the default devices like screen switching to labels. Tip. If a device is already setup in an object than browse button doesn't work. Delete the device and then  press the browse button. then you can select the labels.  

Anytime

CC-Link IE Field basic. Ethernet based network. Attached is the quick start fro the A800 and F800 but is should be similar for the FR-E700. But you will need the  FR-E7NE ethernet board http://dl.mitsubishielectric.com/dl/fa/document/manual/inv/ib0600724/ib0600724engb.pdf CC-Link IE Field Basic Communications.pdf