Rex C100 temperature controller - changing settings Answered
I recently ordered a REX C100 for my electric melting furnace project.
As it came already with a SSR and temp sensor I only added a sensor capable of reading more than 400° of the supplied one.
These controller are dirt cheap and have lots of support in the modding community - although you now can get them new in all variations so no more modding required.
Internally they run on 12V DC, so even mobile use is possible (but this time after modding).
My problem with this controller started with the not included manual.
As it is no China clone but an original from RKC Japan, I downloaded their manual and tried to adjust the max temp settings as well as changing to the thermocouple.
To my surprise the menus for that simply did not exist on my model.
Reading a few more manuals showed that to get to the "initial or factory setup" you need to change the lock code.
Here things get confusing:
Once in the lock menu setting most manuals state to enter "0000" to activate the hidden menus.
(Mine was alreay on 0000)
Others state to set the code to "0100".
In any case you have to hold the setup key for a few seconds to store the changes and after that hold the settings and shift key for about 5 seconds to enter these factory menus.
After being close to send the unit back I tried different code combinations and finally found that "1000" actually activates the hidden menu on my model!
But again there was no joy as several vital settings still did not show up.
To finally get all settings another step is required:
The first item in the hidden menu is "CODE" and it shows as "0000".
After changing this to "0001" the setup key can be used to get to the settings to change the max and min temps.
Once all this done the controller actually shows the selected sensor and if Celsius or Fahrenheit is used at the start and from now on simply by clicking through the hidden menu with the setup key you can get to the min and max temp settings again.
I hope this info will help someone running into the same brick walls as I did...