H0-ECOM 100 and Modbus input registers (30001-3XXXXX)

[lkenison]

I've got a new HO-ECOM100 with the lastest firmware (via a NetEdit download 6-13-08).  I cannot get the module to read Modbus input registers starting at 30001 (64 of them).  I have followed the instructions in the FAQ from 2005.  The FAQ states to use an odd-number in the number of resgister reads.  I did that with the ORD K1 as well as loading a K65.  I still cannot get any input register reads to work.  Has support for input register reads been continued through this version of firmware?  If not, is it possible to get a version that does support input register reads?  Thanks much.
Leon Kenison
Dyer Technology, Inc.

[Greg]

The support for the Input Register reads is certainly continued in the latest version of H0-ECOM100 firmware. In most instances of not being able to get this (or any other Modbus TCP stuff) to work is an addressing problem. For example RX V0 (with odd numbered length configured above it), is an FC04 to 30001.

A sure way to check is to use an Ethernet sniffer (like wireshark.org), and look at the telegrams coming from the H0-ECOM100, and interpret them to see if FC04 is actually happening to the address you think.

Remember when looking at the Ethernet telegrams, FC04 implies the range 30001..., but the telegram itself will show address 0000, not 30001.

Does that help?

[daleale]

A tool I have used to test the H0-Ecom100 is from DACFactory, http://www.azeotech.com/index.php.
The Quick Mod application can be used to read and write and is free. The other stuff in the bundle is trial.