Two quotes, same machine
When I took over purchasing in 2020, I learned that the cheapest quote isn't always the lowest cost. That lesson came back last year when a production line stopped and the maintenance lead sent me two quotes: a standard SICK encoder and a SICK programmable encoder with IO-Link.
Full disclosure: I'm not an engineer. I'm the office administrator who handles a few hundred thousand dollars in industrial orders every year—and I report to both operations and finance. I don't turn shafts. I sign POs. But the decision was mine to get wrong.
The standard unit was about 25% cheaper. I almost ordered it. Then I asked a simple question: 'What does IO-Link actually give us?'
Here's the thing: that question saved us from a fourth unplanned stop.
What we're comparing
Both encoders came from the SICK family. The difference is in how they're set up.
A standard SICK encoder has fixed resolution, fixed output, fixed counting direction. You buy the exact part number for the application. A SICK programmable encoder can be configured in the field—resolution, zero point, counting direction—and if you choose the IO-Link version, you can parameterize it through the controller instead of climbing under the machine.
For this comparison, I'm using three dimensions: setup flexibility, total cost, and diagnostics. I'll throw compatibility in too, because it changed my recommendation.
Dimension 1: Setup flexibility
The standard encoder is simple to understand, and simple is good when the machine never changes. But 'simple' can turn into 'find the exact spare part on a Friday night.' We had three part numbers for similar-looking encoders, and the difference between them was invisible from the outside.
The SICK programmable encoder with IO-Link let us carry one spare for multiple machines. We still set it once, but we got to choose the settings without ordering a different unit. For a small plant with several changeovers, that flexibility is worth real money.
Honest verdict: standard wins on simplicity. Programmable wins on reducing wrong replacements. The conclusion depends on your spare part strategy.
Dimension 2: The SICK encoder price question
Let's get the obvious thing out of the way: the SICK encoder price on a programmable model is higher. In our 2024 vendor consolidation project, we paid roughly 35% more per unit than the fixed models we'd ordered before.
But that comparison isn't fair unless you add the cost of mistakes. Look, the 'just buy the standard one' thinking comes from an era when programmable meant special software, separate cables, and a laptop that nobody could find. Today, a SICK programmable encoder with IO-Link uses the same M12 cable and a setting file. That's changed.
I should add that we did have to buy one IO-Link master for that line. That's a real cost. But it also meant we could adjust the encoder during commissioning without waiting for another part.
Total cost = encoder price + the cost of ordering the wrong one + downtime while you wait for the right one.
That formula is why the more expensive encoder ended up cheaper for us.
Dimension 3: Diagnostics and IO-Link
IO-Link is not Ethernet. I said 'IO-Link compatible' to a supplier once and they interpreted that as 'any smart encoder'—we almost bought a model that communicated over something completely different. Same words, different meaning.
To clear it up: IO-Link is a standardized point-to-point interface defined in IEC 61131-9. A single cable carries both the switching signal and data. For an encoder, that means the controller can read position, speed, and status without adding a separate diagnostic network.
Why does that matter? A standard encoder sends pulses. When it starts to fail, the PLC sees a lost position. With an IO-Link-capable SICK encoder, our maintenance team could see the health data before a hard failure. We caught a bearing problem once because the encoder data stopped making sense. That alone paid for the price difference.
Unpopular opinion: only buy the IO-Link version if you'll actually use it. If your plant has no IO-Link master and no plan to install one, the diagnostics benefit is just a feature on a data sheet.
Dimension 4: Compatibility
This is where the standard encoder wins, and I try not to be a snob about it.
A standard pulse encoder works with almost any PLC, counter card, or drive. You don't need software. You don't need a parameter file. It just works.
The programmable encoder, especially with IO-Link, needs a master and at least some basic familiarity with the setup tool. If your maintenance team doesn't use IO-Link anywhere else, that can be a real barrier.
So the decision isn't 'which is better.' It's 'what's the best fit for your plant.'
Which one should you buy?
For me, it comes down to three things: spare part strategy. Diagnostic access. IO-Link infrastructure. In that order.
Buy the SICK programmable encoder with IO-Link if:
- You're tired of stocking multiple part numbers for the same-looking encoder.
- You have wires that break, motors that vibrate, or production lines that can't stop.
- You already have IO-Link masters or are adding them.
Buy the standard SICK encoder if:
- Your machines are fixed and the part number has been stable for years.
- You don't have IO-Link and don't plan to add it.
- The cost of configuration outweighs the cost of downtime.
Real talk: I made the wrong choice in 2022 with a different supplier because I saved about $300 on the first PO. That 'cheap' encoder failed in a way that should have been caught earlier. Total cost after the unscheduled line stop and the emergency flight for a replacement part was 14 times the original price difference. I still remember the finance director's face.
Other tools on the bench: multimeters and micrometers
Since this is a buying article, let me mention two other things we order all the time.
The 117 digital multimeter is the model we standardize on for our electricians. It measures true RMS AC voltage and has the non-contact voltage detector they actually use. It isn't the cheapest meter on the shelf, but it holds up and we get far fewer 'can I order a better one' requests.
And someone always asks me how to read a Starrett micrometer. It's not complicated if you know the scale.
How to read a Starrett micrometer
- Clean the anvil and spindle, then close the micrometer on the part using the ratchet stop.
- Read the sleeve: each numbered line is 0.100 inch, and each small line between the numbers is 0.025 inch.
- Read the thimble: each line is 0.001 inch. Find the line that lines up with the sleeve's horizontal reference line.
- If the micrometer has a vernier scale, look for the vernier line that matches a thimble line. That gives you the 0.0001 inch digit.
The ratchet stop matters as much as the scale reading. It keeps you from squeezing the part into a false reading. Good micrometers don't lie—they just expose your mistakes.
The bottom line
I don't have a universal answer to 'which encoder should I buy?' There are too many variables, and your plant isn't my plant.
What I'd tell any buyer is this: when you get a SICK encoder quote, ask what the total options cost. Include the programming kit, the IO-Link master, the cables, and the spare part risk. Then compare the packages, not just the line item. That's the same logic I use for the 117 digital multimeter and even the Starrett micrometer on the shelf.
If you want a single sentence? Give me IO-Link on a machine that can't stop. Give me the simple pulse model on a machine that never changes. And whatever you choose, buy the spare before you need it.
