Crossbow

If you open help in Sysmac Studio with a code window open, it's all documented there.  Never seen that file available as a PDF though...

The HMI has access to all memory areas in the CPU, including numeric. I don't get where serial comm and a weigh scale comes into this.  If you want a third part device to talk to the PLC, it needs to talk one of the PLC's supported protocols.  And RS232 is a single device connection, so if you are already using the RS232 port for the HMI, you can't also use it for another device.

WR3A is only used for the FX0N-3A, which is 2 analog inputs and 1 analog output. Check the manual for your analog card, it will have a complete list of registers in it.

I agree with Panic Mode.  Don't touch the safety until a qualified safety programmer has written and tested a program.  It's not as simple as working with a regular PLC.

SCL is useful for creating a scale which is non-linear.  It's a bit complex if all you need to do is convert 0-4000 into 0-100.  Math is far easier. As I mentioned, some of the newer cards have a user selectable range so it can be done in the card before the program ever sees it.

You need to determine what your application is supposed to do, and write a ladder program to run it.  PLCs are not intended to be controlled from a text app like HyperTerminal.  If anything, it would be used to display data the PLC sends out a serial port telling status.  PLC still needs a program.

Never seen such a board.  No idea who the vendor is, so can't help you.

Clearly someone did not read the terms of service and would like to be removed from this website.  

You will scale with math instructions in the CPU.  The module offers a couple input resolutions.  Q64ADN (newer version) if I recall had a user configurable range.

Not that I am aware of.  But then you also didn't say what Mitsubishi PLC and there are dozens of them.

Same reply as on your Omron post.  Discussing bypass of passwords is not allowed. 

Contact the original machine builder.  Passwords are for protection of intellectual property, and you agreed not to talk about illegally bypassing passwords when you made your account here.

But did you make variable names in the PLC?  Did you set them to Network Publish? NA is not designed to see PLC addresses, only variable names that are available on EtherNet/IP. If you already wrote the program with addresses, you can assign an address to a variable when you create the variable, so you don't have to write the entire program with variables if you prefer not to.

Immediate Stop is meant to be like a safe stop function, it's speed of stop is based on physical forces.  No deceleration is applied, so yes it will change based on the speed. You're going to need to decel the axes to make them stop at the same time.  Just use a very rapid decel rate, and calculate it based on the speed of the axis, so they can stop in the same amount of time.

The Sysmac HMI is designed for use with variable names.  You need to assign variables in the CJ controller, set them for network access, and then import them into Studio, and then use them to create your screen objects. The NS and NB Series HMI products are designed for use with CJ addresses.  NA is really designed for use with Sysmac NJ/NX controllers.