GE 90-30 vs. DL205

I've been reading I/M's etc. on these two PLC models and am unclear about several things:

1)It looks like the DL-205 max's out at a nine slot rack and 128 I/O. Beyond that, you need a remote adaptor and other special hardware. Am I seeing this correctly and, if I'm going to be somewhere around 240 I/O, is the cost impact large compared to the 90-30 where, it seems, a second 10 slot rack and a short cable is all that is required.

And, 2), at 240 I/O with about 100 DC inputs and 140 DC or relay outputs, is there a significant total cost difference between the two systems if I buy used/surplus like on ebay?

And, 3) for home automation/hobby use, is it feasible to use the handheld programmer rather than, what seems to be, exorbitantly priced PC software? What do I give up by using the handheld unit?

Thanks again for your replies. It's been really helpful, so far.

Dick I think the DL205 racks max out at 256 I/O , the manual states:

The DL205 CPUs can support up to 256 I/O points with the bases currently available.
These points can be assigned as input or output points. The DL240 and DL250
systems can also be expanded by adding remote I/O. The DL250 also provides a
built–in master for remote I/O networks. The I/O configuration is explained in
Chapter 4, System Design and Configuration.

The software for just the DL205 lists for $199.

Any brand you go with the software will be the hard part. Ebay is a good source for finding a system inexspensively. Just an FYI the GE Series One is the same as TI 305, Siemens 305 and DL305 from automationdirect. Its possible to find a handheld programmer for those too.

The easiest of the 2 you stated to find on the net (ebay etc) will probably be the GE Fanuc 90-30. Its also a good possibility to obtain the old dos software for GE Fanuc (LogicMaster 90). I recently purchased Versa Pro for the GE Fanuc 90-30 and I think the list price was $387 (I may have my numbers wrong, not positive about this) or somewhere in that area, so its not priced that bad compared to some.

Let me know if you need any assistance.

Reply to RS Doran

Thanks for answering, RS. In the DL205 users manual on pg 3-4 in a chart showing general specs for the 230/240/250 CPU's, it shows max Local I/O available for all three CPU's as 128. This would correspond to a nine slot rack with CPU and 8 x 16 point modules. The 230 CPU shows no remote I/O available, and varying large amounts of remote I/O for the 240 and 250 CPU.

My concern is how expensive and awkward it might be to add remote I/O to the first rack.

To get 256 I/O in a nine-slot DL250, you'd need to use all 32-point modules. If you need relay outputs, you're out of luck, max is 16 points. Be sure to check the current requirements of your output devices against the capacities of the output modules. DL205 DC output modules are rated at 200 mA for 8-point DC outputs, 100 mA for 16 and 32 point. The 90-30 DC output modules are rated at 500 mA for 16 and 32 point, 2 A for 8-point.

I personally have never used DL205 remote I/O, but I wouldn't hesitate if the job required it. It's not inherently difficult. Just remember that the remote I/O may not be updated every program scan. That's usually no problem, but it's a fact you should be aware of.

If you're buying new hardware, you will probably pay more for a 90-30 system than a DL205. For any programs you're likely to write with only discrete I/O, the instruction sets are pretty much the same.

If you use 32-point I/O modules, you also need to purchase or make cables to plug into them. If you use 8 or 16-point modules, the wiring is to terminals on the modules. The DL205 is physically smaller than the 90-30, with correspondingly less room for the wires. Fortunately, you only need to wire the beast once.

I wouldn't bother with the handheld programmers for either brand. They don't show an entire rung of ladder logic, just the individual instructions with their addresses. Furthermore, you can't have rung comments or names with a handheld, and you need a seperate memory card to store each program. In the case of the 90-30, the newer CPU modules are not compatible with the handheld, and a license for VersaPro software for the 90-30 costs less than the handheld.

I am not that strong on the DL205 but we have some and I have the manual(s). I believe they also have 32 point modules.

I think Steve stated it clearly but you did have a question about cost. Off top of my head I think buying all new its gonna cost over a $1000. With automationdirect you can get all the prices and get a good idea. Overall they are cheaper than others.

I agree with Steve about buying the software, its better in the long run. Handhelds are slow and there are alot of other issues that make the software much more desirable.

You may want to think about getting something like GE Fanuc etc online and purchasing the software. May save you 100's of $. The problem with that is Buyer beware.

The ADC (AutomationDirect.com) 250 is my favorite PLC, and the GE 90-30 is my second favorite. You should enjoy working with either of them.

As far as the remote I/O for the ADC 250 goes, you have two choices. On older systems you use a remote master controller in a slot on the master, and remote slave module in each slave I/O rack. You have to do some configuration in your ladder logic and set some dip switches, but it isn't too tough and is much easier than some other manufacturer's remote I/O. You can have up to 8,000 total I/O points with this system, depending on processor.

On a new ADC system you can add expansion I/O for under a hundreD and fifty bucks. In this case the remote I/O is updated every scan. You add an I/O expansion module to the end of the master rack, and use an I/O expansion controller in each expansion rack. This system is new, so I don't know if any programming is required for this configuration. You can have up to 1,200 points with this system.

Thanks

As usual, good solid answers and right to the point. I should be so lucky.

Thanks again!

FYI.

Something that you might want to consider is to go to AD's website http://www.automationdirect.com and look at the NEW 250-1 and 260-1 CPU's.

Both of these new cpu's offer local expansion capabilities. The 250-1 is the same as the old 250 with the local expansion base capability.

The 260-1 is a powerhouse for a micro plc. 16 PID Loops and host of other features.