ControlLogix -L73 vs guardLogix -L73S

[Secpcb]

I have a project I want to get a L73 ControlLogix CPU for. I have a rack, power supply and a few cards, so I need a CPU, EN2T & some cards.


This is a budget build in-house so eBay is the supplier of choice.


When looking for the L73 they start at $1200, but the GuardLogix -L73S CPU's start at $600 - half the cost.


This isn't a safety project, but I was wondering if the GuardLogix can be used here for the $600 savings - just not program in any safety features.


Also wondering why the GuardLogix's are half the cost if they are supposedly a better CPU? Or are they not usable as a standard CPU?

 

[dmroeder]

If you buy the L73S, you must buy the safety partner with it (L7SP). You cannot use the L73S without the safety partner.

Edit: You are also comparing ebay prices for used hardware. For us, a L71S is more expensive than a L71, that is without the cost of the safety partner.

 

[jstolaruk]

I have a Controllogix I use at my desk for s/w routine development. The least inexpensive system I was able to put together was a 1756-L61 and a later version of the 1756-DNB that has a USB connection on the front (for programming). Over the years I've added other modules (ENBT, EWEB, IF8, DHRIO, L61S+LSP) as I came across them cheap. The downside is that the s/w version is limited to v20.05 but for the majority of testing, it doesn't hinder.

 

[Secpcb]

Dmroeder, thanks. I was sort of thinking this was why they were cheaper.


Jstolaruk, the v20 issue is why I'm going with the L70 series. Version 20 has a limitation on the Ethernet communications I will need. As soon as I change to v26 (or 32) and a L73 so much more is available with the same EN2T.

 

[Contr_Conn]

Version 20 has a limitation on the Ethernet communications I will need

Can you be more specific on what Ethernet functionality is missing in V20? You should have the same communication features of EN2T when used with L6x V20 or L7 in V32

 

[Phil Buchanan]

I am not sure why but many times a Guardlogix with SP can be had on eBay for a price lower than the same family standard processor with the same memory capacity.

I buy a lot of gear on there both standard processors and GuardLogix both for low-budget customers and for students in my PLC Boot Camp classes to bang around on.

I have a customer that wants to upgrade 2 5/04 to 5/05 so they can be added to the ethernet network like everything else (he is opposed to using a gateway)but the cost of the used 5/05 on there are crazy also and not much cheaper than NIB from the distributor.

 

[I_Automation]

Can you be more specific on what Ethernet functionality is missing in V20? You should have the same communication features of EN2T when used with L6x V20 or L7 in V32

I had a project in ver 20 that I ended up upgrading to ver 26 with a newer CPU to use some devices.

Ver 20 would not let me add items to the IO tree under the Etherenet module EN2T, it would only let the CPU message through it.

 

[dmroeder]

I had a project in ver 20 that I ended up upgrading to ver 26 with a newer CPU to use some devices.

Ver 20 would not let me add items to the IO tree under the Etherenet module EN2T, it would only let the CPU message through it.

This is just the software being difficult. You can add pretty much anything into the I/O tree regarding controllers as long as the path is correct. For example, you could add a ENBT to your tree and a L61, even though the device on the other end is actually a L71 and EN2T, it will still communicate.