Howto choose modbus tcp functions with dsc 8.0.1 / DSC register numbering explanation

[computerkammer]

Hello,
after reading in the discussion forums I still cannot solve my DSC Modbus problems.

First I'm confused about register numbering.
Playing around with the registers, which the multiple variable shows, give me the finally success polling values:
Registers in device documentation: 0x0000 - 0x0007 Finally I found them on 300001-300008 

Question: Why is the leading 3 needed....?

Sniffing with Ethereal shows me "function 4" is used for reading by Labview.

Question : Howto use Modbus function 3 or (for writing) 5, 6, 15, 16, (read and write) 23?

My biggest problem at the moment:

I want to read register 0x1010 = 4112d it contain a length of process data byte in packed format. Reading ends in exception 0x8BBB0005

Thanks in advance for an answer or just a link with similar problems

[unclebump]

You have different types of registers inside a controller. 3xxxxx are input registers and 4xxxxx are holding/output registers. Check out the attached pdf file.

Message Edited by unclebump on 07-26-2006 02:04 PM