CTI 2572 Ethernet NIC

We have six NICs for Siemens 505 chassis at our place, and four are acting normally.

Two are not able to complete set-up. I have tried both the CTI Diag utility for Windows, and the 2572IPSET for DOS utility; they have similar but not identical results.
I am trying to set the cards to IP address 192.168.3.7x, and a router of 192.168.3.1, and a subnet mask of 255.255.255.0, and (default)port 1505 .

The bizarre part is that I can change the IP, router, port at will, and the change takes effect. However both cards will always reset their net masks.

The card does a READ to show me the present values, then I choose to WRITE, and it does a confirming READ. I will only show the netmask result here, as all other fields work fine.

Card1: using 2572IPSET
trial 1 WRITE 255.255.255.0 READ 10.53.0.22
trial 2 WRITE 255.255.255.0 READ 10.65.0.22
try IPSET /I (display only) reads 10.64.0.22
trial 3 using CTIDiag WRITE 255.255.255.0 READ 115.221.233.0

Card 2: using either
all trials WRITE 255.255.255.0 READ 10.20.0.22

I have also tried setting the mask to 0.0.0.0; results are same.
Yes I have tried with and without power cycle between the Write and another Read - no difference. Please recall that I have successfully configured four other cards, so I know what they should be doing.

The EEPROMS in the cards are both dated 1995; one is version 2.0, the other version 4.5. CTI tech support has suggested that the EEPROMS are 'fried', however this seems like a mighty selective failure for both cards to have almost identical problems. As well, the difference between reading the one with CTIDiag versus 2572IPSET is also exceeding strange.
I tried swapping the EEPROMS in from one of the newer cards, but I could not even go on-line with it then.

CTI want to sell me new rev. B cards to solve the problem.

Ideas, anyone?

Are these cards in a PLC with a program running? Way back in the day, you set the IP addressing via ladder logic. Is there a chance you have a bit of logic overwrite?

No, Ken, they are in my test bench rack.

I know that setting the address can be done two ways: the utility or through logic. I thought it more expedient to use the utility. There is no logic overwrite - they have unique addresses the program in nothing but a single END statement.

I've not tried the logic method, but I shall.

I always liked the logic method more, as that way I could replace a card as needed w/out having to reprogram it.

Also, with the age of those cards, If there was a previous set of logic that wrote to the EEPROM it could conceivably have damaged specific portions of the flash.

When using PLC logic, set dipswitch 4 on SW2 to "open". This tells the module to use PLC Start instead of Auto start. Auto start uses the information from the EEPROM.