CD101 PID Controller stop mode issue

The CD101 is an inexpensive (under $40) PID controller sold by Sure Electronics. Aside from the incomplete documentation that is shipped with the unit, I’m pretty happy with this controller. I’m planning to use it to replace the failed PID controller that controls my soldering hotplate.

I am having one small issue with the CD101 – stop mode doesn’t seem to do anything. By that I mean it doesn’t disable the outputs or seem to affect the controller in any way. Based on my interpretation of the user manual, the outputs and alarms should be disabled in stop mode. This is mostly an annoyance in my application – if I want to disable the hotplate I’ll just turn it off. However, I can imagine that the lack of a standby mode might cause problems in some applications.

I contacted Sure Electronics about the problem, and they requested a video. I figured I might as well post it here, since I went through the trouble of making it and everything. 🙂

By the way, since it can be hard to find information on this controller (eg. how to change from Fahrenheit to Celsius display), I have been slowly putting together a wiki page for the CD101.

PS: The video was shot with my new Canon PowerShot S95, which seems to take great footage, except that there is no autofocus or zoom control while shooting. (?!)

28 thoughts on “CD101 PID Controller stop mode issue”

    1. Also measure the voltage when the voltage pulse output is on and make sure it is 12 VDC. If it is less then you may have an 220 VAC transformer rather than a 100 -240 VAC switching power supply. If that is the case you need to provide a 220 VAC power source for the thermocouple to read properly.

  1. I have a RKC REX C-100 PID temperature controller from CHINA they are a different revision than the RKC REX C-100 PID temperture controller from JAPAN. Do not throw out the Chinese double sided instruction sheet because the Initial Setting parameter labels have the same names, but the parameter values are not the same.
    For example the LCK code to get to the Initial Setting parameter is 1000 not 0000. The SL_1 input type parameter for 100 Ohm Platinum RTD is 1000 not 1100. The parameter tables are closer to the CD-101 controller layout than the C-100 JAPAN controller. The initial setting parameter tables are two tables Cod 0000 and Cod 0001. In the Cod 0001 table you can only see the decimal point setting parameter if you use the 100 Ohm Platinum RTD type. (PGdP set to 0003 for 000,0 deg C display resolution.) The PGdP parameter does not appear in the Cod 0001 table when set to the type K input 0000. Change the Cod value between 0000 and 0001 to scroll through the two tables. SL 2, 3, 8, 9, 10, and 11 are omitted like the CD-101 table parameters. Using the SL_2 to change deg C to deg F (0000-0001) did not work for me.

    1. I have also found two different power options from the C-100 controllers from China.
      Option 1 is a 220 VAC transformer and Option 2 is a 100 to 240 VAC switching power supply which was not in the specification section or EBAY pictures of the Dual Digital F/C PID Temperature Controller Control E12 from lijiestore2009 in Hong Kong for around $18.00 total with shipping to USA. It came with the 100 to 240 VAC switching power supply, I swapped out the type K thermocouple with a 100 Ohm Platinum RTD and have it set at 000.0 deg C resolution. Next I am going to unsolder and remove the 12 VDC 10 Amp output relay and jumper the 12 VDC signal to the relay coil to the relay output terminals. I will use it to drive a Solid State Relays SSR 3-32V DC Output 24-380V AC 25A (about $5.00 total from Ebay Member id also out in Hong Kong) Remember to change the T proportional cycle time from 20 seconds to 2 seconds when switching from relay to SSR. Finally do not forget a heat sink for your SSR if you are pulling above 10 amps through your SSR. Sous Vide water heater above 1kW.

      1. Update For my REX C-100 from RKC Instruments in CHINA.
        PGdP set to 0003 or 0002 or 0001 000,0 PV 0.1 deg C display resolution
        PGdP set to 0000 for 0000 PV 1 deg C display resolution
        Default PGdP set to 0001 for 000,0 deg C display resolution on CD101
        Any value above 0 for PGdP gave a 0.1 deg C display resolution for my REX C-100 from RKC Instruments in CHINA.

        1. Thank you for the update! I checked mine, and, oddly, the lck function only runs from 0-255… any thoughts?

          1. The parameter tables on the one I have are closer to the CD-101 controller layout than the C-100 JAPAN controller. Your unit sounds like the version that you need to set your LCK code to 0000 to get to the initial setting menu. I think the setup menu will more closely follow the Japan REX C-100 menu layout. Look at the Chinese documentation that came with your unit and you may be able to match it with the English language initial settings manual. That’s what I had to do with mine because even thought I was able to find a menu layout that was almost the same, the parameter values did not match between the Chinese and English manuals. I was lucky I was able to retrieve the sheet from the trash before it was too late. If you tossed it already, check with you seller to get a set of instructions from the manufacturer.

  2. Hi Sebastian,
    I’m also the “lucky” owner of a fake rex c-100 bought on ebay.
    I’m having the same problems you are having.
    The only answer I got from the seller is that these controllers are 220v only…
    I’ve got a partial refund.

  3. Ha, yeah, hi-jacked the comments. My apologies. Jumped to the forum in “General Discussion.”

    And yeah, it’s totally the knock-off version. Just hoped someone had deciphered it before me.

  4. Sebastian,

    If you paid $25 and it shipped from China, then it is unlikely to be a real RKC PID controller like the one you linked. It will be probably be like the CD101 we have is a fake/copy of the real RKC CB101. This means it is very likely that it will not operate exactly as per the RKC documentation.

    If your temperature readings are incorrect, then you may not have selected the correct thermocouple type.

    Yeah, the forums are probably a better place for this.


  5. The rkc c100… any info on this thing? the stated settings and simultaneous button-pushing do not work. this is my second unit from china and i am getting a touch frustrated with it all (plus, the picture on ebay was from a cd101 to boot… ugh).

    as soon as i fire it up, the pv jumps through the roof. without it plugged in, i get a reading of 750-850.

    any ideas?

    thanks so much!

    1. I’ve never seen a c100, so I’m afraid I can’t help you. Best bet is to try to talk to whoever sold it to you (if you share a common language with them…)

      1. common language is hard to come by in the cheap-as-hell PID temp controller market! ha! thanks though. if i come up with something, ill get back to you as these things are sold next to the cd101’s on ebay.

        1. Can you share a link to one? I did a search and I can’t tell from the C100 listings on eBay which one you’re referring to.

          1. that one is way too expensive. i bought mine for about $25 shipped form China.

            btw, do you know about wiring these things? when the thermocouple is wired into the terminals, it reads too high, but when nothing is plugged in, it reads as 750-850. does the cd101 do that?

            the over read looks like a short circuit, but that is impossible because it is brand new today.

  6. Thanks Jeff.

    As you know, that doesn’t correspond with the published manual, nor the traditional run/stop concept in industrial automation. Unfortunately that is what you get with low cost copies of equipment.

    It would be interesting to know if the real RKC CB series PID controls do the same. Both the Sure and RKC manuals state that in stop mode “Control output OFF, Alarm output OFF”. Could be a safety issue if these find their way into industrial plants, rather than just hacker labs…

    Love the blog!

    1. Kean,

      Yeah, the manual clearly states that the control outputs and alarms should be off in stop mode. I responded to Sure asking about that and they haven’t returned my e-mail. My guess is that it’s a bug that they don’t feel the need to address.

      As you said, you get what you paid for with these controllers…

      Oh, and thanks! 🙂

  7. I also have a CD-101 from Sure Electronics. I used it for a while to test out a custom heating element for our Makerbot. I also couldn’t get the Stop mode to function, so it would be great to find out what Sure have to say.

    1. I recently received this response from them:

      Dear Sir,

      Thank you for your waiting, we have contacted the technique team that the display shown in the video shows the PID is working. So the item is not faulty.

      As to the STOP we menthioned in the manual, it means when you press the STOP, the ALM will stop output. It does not mean it will stop OUT1 and OUT2.

      Thanks a lot for your cooperation and understanding.

      Have a nice day!

      So they claim that stop mode only disables the alarms (I haven’t checked this) and not the control outputs.

  8. Hi Jeff,

    Through trial and error I have determined that SL10 Bit 1 controls the STOP mode and bit 4 controls Self Tune mode.

    e.g. SL10
    0000 = Self tune disabled, stop mode disabled
    0001 = self tune disabled, stop mode normal (still inop)
    1000 = self tune active, stop mode disabled

    1. David,

      So it’s possible to disable the STOP feature completely, but when it’s enabled it still doesn’t do anything?

      Also, can you please add your SL10 results to the wiki?

    1. Thanks, it’s good to know I’m not the only one having this problem.

      I’m still waiting to hear back from Sure. I’ll post here when I do.

  9. Hi Jeff. Have you found a way to get the CD-101 to display a decimal point? The additional instructions don’t seem correct for my device as the secret menu options are not the same a the ones shown in the instructions. Our devices are definately clones of RKC instruments (likely the REX C-100 series).

    1. David,

      I have documented all of the “secret” settings I know of on the wiki. There are probably others, but I’m not aware of a way to display a decimal point.

      Unless you’re using a super-accurate RTD sensor, I wouldn’t trust the decimal anyway. My understanding is that thermocouples are typically only accurate within 1-2C, and who knows how accurate the CD101 is, anyway.

      I had assumed they were RKC knockoffs, since RKC doesn’t make a model CD101.

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