Memory Problem - GE 90-70 PLC

Dear All,

I would much appreciate comments on the following problem which i am currently facing:-

We currently have a GE Fanuc 90-70 PLC (Model:IC697CPX935) up and running on our process. This model of PLC contains 1MB fixed user memory out of which only 544KB can be used for ladder program. We would like to add a few new mods into the PLC but currently the memory is 91% full.

I have see another model of 90-70 PLC (Model:IC697CPX928) having 6MB memory out of which only 1MB can be used for Ladder program (this will be sufficient for the new mods). I would like to replce my CPU with this model. Can you all please share experiences if this is just a case of replacing CPU's and downloading the program or does it involves anything more that i am not seeing .

Many thanks in advance.

I would say, it is just changing the HWCFG and download it. But think about replacing the 90-70 with the newer RX7i. Programs should be compatible (if there are no 3rd party VME modules in). A local GE Fanuc engineer would help you for sure to analyse it. And you would have CPUs with up to 64 MB RAM and rocket speed symbolic adressing function blocks and all the fancy stuff what you miss in the 90-70. You would need Machine Edition for programming. But all the existing modules can be kept. Only Chassis, power supply and CPU with integrated Ethernet is to replace. The RX7i is cheaper than 90-70 and you will be ready for future enhancements.

Joern

Mammoth,

Many thanks for your reply. Have you heard if GE fanuc are planning to stop production of 90-70, 90-30?? I keep hearing rumours about this. Can anyone share their experiences please. Many thanks.

Has RX7i got the same capability like a true DCS? I mean advance process control, SPC, maintance, planning, production optimisation etc etc.

I didn't hear this. Especially the 90-30 has a hughe installed base and some new CPU's were released recently. But, with the migration from Series 90-xx to RX..i GEF made a simple way to upgrade to that family. Most of the 90-30 modules can be used in RX3i and programs are 99% compatible. For spare parts I don't see a problem for the future. There are still Series 6 spare parts available. This was a PLC in the 80s.
If you have a DCS and want to compare the capabilities between 90-70 and RX7i you can call Steve W. from GEF in Towcester office. He is very familiar with process systems. The RX7i is not a DCS itself, it is a PLC which can be used in a PPS. There is a product/products available which will cover your requirements.

I did a conversion from 90-70 to 90-30, and other than a few commands unique to the 90-70, it was nearly a flawless conversion. The commands (logic) were easily changed, and we were running on the new PLC in a few days, from start to finish.

I also made a change to a remote 90-70 to a 90-30, in the field, took about 2 hours tops!

Using GE Proficy, of course. Just FYI.

FYI GE does have a "trade up" program that gives a 40 - 60% processor discounts when moving from 9070 - Rx7i or 9030 - Rx3i.

Not a bad route to go especially since you can reuse the old IO modules.