What are your ControlLogix IO type preferences? Why?

[JLand]

I'm possibly the world's biggest critic of Rockwell kit and have had some strong worded emails about their Flex range of IO, but Flex5000 is my favourite.

I would add to the above that removing the stickers before putting the cards in is a strict requirement not to break them... had an apprentice break two of them in a project because he didn't remove the stickers and bent the pins.

The other IO I really, really like is the 1719 Intrinsically Safe IO modules. The only complaint about them is that they're very strict on error detecting in the analog channels. 3.9999999999999 is an immediate channel failure as far as the cards are concerned which gets annoying very fast. On the other hand, the HART interface is pretty sweet, but that's mostly on HART functionality not necessarily these particular cards.

In all fairness to 1719 ExIO, in an explosive environment you really shouldn't be beyond the normal operation design limits of the hardware. If you're constantly going below 4mA, even by 10 femtoamps, I'd argue you have the wrong sensor for the job.

 

[creativepaper]

I use PointI/O - 5069 is last project and it was great for remote cabinet based IO.
You can mix normal and safety IO modules (if using guardlogix PLC), which is nice.
Downside of their safety Input cards. They do not support OSSD. You need to configure a hardwire filter on the card (potentially a firmware upgrade on the card as well)


We use SMC EX600 for non-cabinet remote IO (I'm sure Festo is the same). They are wicked cheap and very reliable, esp using connectors (M8 or M12) means that we don't need a cabinet and can have pneumatics on the same chassis.

We've been using CompactLogix (or guardLogix) L300 series and they are so fast that we have multiple skids onto 1 centralized PLC instead of multiple PLC's

 

[joseph_e2]

Another vote for the SMC EX600 stuff. At my last place, we had a choice between SMC and Festo for a networked valve bank controlled by a CompactLogix. SMC won mainly because their local rep was better able to get us a sample to test before buying. We'd also had some "random" failures with Festo bus modules (on Profibus) and some lead time issues so weren't super sold on them anyway. As far as I know, that system has been running about 10 years without hiccup. We now have 3 (soon to be 4) EX600s in service here. The only issue we've seen is a failure in a 24VDC digital input module when there was a shorted sensor cable. Had to replace the module under warranty. Even with that, I wouldn't hesitate to use them again in a setting where we needed a valve bank too.

 

[robertmee]

I use PointI/O - 5069 is last project and it was great for remote cabinet based IO.
You can mix normal and safety IO modules (if using guardlogix PLC), which is nice.
Downside of their safety Input cards. They do not support OSSD. You need to configure a hardwire filter on the card (potentially a firmware upgrade on the card as well)


We use SMC EX600 for non-cabinet remote IO (I'm sure Festo is the same). They are wicked cheap and very reliable, esp using connectors (M8 or M12) means that we don't need a cabinet and can have pneumatics on the same chassis.

We've been using CompactLogix (or guardLogix) L300 series and they are so fast that we have multiple skids onto 1 centralized PLC instead of multiple PLC's

I dont consider lack of an imbedded dual channel OSSD on safety inputs a handicap. I haven't used that on safety since the very first advent. Better to configure all safeties as singles and use the appropriate safety instructions, IMO.

 

[creativepaper]

I dont consider lack of an imbedded dual channel OSSD on safety inputs a handicap. I haven't used that on safety since the very first advent. Better to configure all safeties as singles and use the appropriate safety instructions, IMO.

We have a Rockwell safety switch that outputs single or dual OSSD. The inbuilt Rockwell safety functions would fault out when it did the blip.
Rockwell's response was a firmware upgrade and the ability to put in a 10ms filter to filter the blip out.
Their CR30 programmable safety relay likes OSSD, just their 5069-Point IO safety input don't

Apart from that, I like the guardlogix for anything that requires more than a relay

 

[cardosocea]

In all fairness to 1719 ExIO, in an explosive environment you really shouldn't be beyond the normal operation design limits of the hardware. If you're constantly going below 4mA, even by 10 femtoamps, I'd argue you have the wrong sensor for the job.

What do you consider the normal operation design limits of the hardware? What hardware? Card or IO point?
How is going below 4mA impact the intrinsically safe circuitry of the card and circuit? More importantly, where is Rockwell or P+F calibration certificate to 5 femtoamps precision?

Of course, I can just as well scale my temperature transmitter between -5 and 125 and be done with it, but it gets annoying fast to consider that the card doesn't have an hysteresis.

 

[kekrahulik]

We have some 1794 Flex. Works until it doesn't, and then we have often suffered downtime until we replaced multiple cards and backplanes.

We use a lot of 1734 Pt IO - especially for the safety cards. Much has to be configured offline with a download to install

1756 has been very reliable and has the convenience of online additions/removals etc. We use IFM wiring modules for most of the cards. They now have 1756-IB16S and 1756-OBV8S for safety applications.....HOWEVER....the 1756-OBV8S cannot pull in the 10no/2nc contact 700S-DCP1020DZ24 Estop relays we use throughout the plant. I am completely baffled how AB had the the 1734 PT IO capable of pulling these relays in and then creates the latest and greatest 1756 card that cannot. The best I can do is to use a 700S-EF620QJC relay that has 6no/2nc. So I have no plans to use any more of the 1756 safety cards.

I haven't used the 5000 stuff yet. It looks good, but I'd need to investigate the safety side first.

 

[JLand]

What do you consider the normal operation design limits of the hardware? What hardware? Card or IO point?
How is going below 4mA impact the intrinsically safe circuitry of the card and circuit? More importantly, where is Rockwell or P+F calibration certificate to 5 femtoamps precision?

Of course, I can just as well scale my temperature transmitter between -5 and 125 and be done with it, but it gets annoying fast to consider that the card doesn't have an hysteresis.

I generally would try not to go outside the design specs of a device in a potentially explosive atmosphere, even if my gut said it was fine.

Normal design limits of a 4-20mA device would be process conditions within (and including) whatever process variable scales to 4mA and 20mA. If a 0-150psig pressure transmitter went below 0psig or above 150psig, I would say that is outside that device's design specs.

 

[cardosocea]

I generally would try not to go outside the design specs of a device in a potentially explosive atmosphere, even if my gut said it was fine.

And this is why you have I.S. circuit certificates and the X condition to mark for anything out of the ordinary.

Normal design limits of a 4-20mA device would be process conditions within (and including) whatever process variable scales to 4mA and 20mA. If a 0-150psig pressure transmitter went below 0psig or above 150psig, I would say that is outside that device's design specs.

You never had noise on the line or a slightly jumpy flowmeter at 0 when scaled for really large flow numbers?

I get what you're saying and ultimately rescaling because of this is a minor inconvenience in the grand scheme of things, but still annoying.