This os a manual for the rec 100 that works for the chinese model.
http://style.oversubstance.net/wp-conte ... X-C100.pdf
Hello All,
I've seen a lot of people writing in frustration after buying a very cheap Rex C100. There is an official Japanese one which has a complete manual, this is about the clone/knock off version, which can be ordered on ebay, complete with a SSR for around a tenner.
This post is not about bypassing a rely to directly drive the SSR, nor is it about the SSRs themselves, more a record of all Ive managed to piece together having spent a large amount of time experimenting and googling how to get this little bundle of horror to work well. In the end, Ive learnt a lot more than I would have, were I to have bought a nice new sestos and had it work out of the box., so I am actually not too annoyed...
So. To sumarise, i got a Berme/RKG/whatever C100 complete with SSR and soon found that there is no decent documentation. Anywhere. It also came with a bit of a rubbish K thermocouple. I ordered some cheap 2wire PT100s, to use instead.
First of all, I mounted the 2 PIDs in an external waterproof box, with the SSRs on an aluminium sheet.
As you can see, i wired extension cables to the sensors. Its hard to see as this is all now installed, but I soldered these cables direct to the board, to avoid weak connections, which would alter the readings. I broke the plastic case out to allow the cables to poke trough too.
Now, once the PT100 cables are connected, to pins 8 and 9, i shorted pins 8 and 10... A three wire sensor might allow for automatic compensation for the overall wire resistance, but we can work around that later using the adjustment in the PID.
So this is where it got stressful. There are 2 menus, to adjust settings, one is accessed by holding the SET button for 2 seconds. This allows adjustment of the following settings...
AL1 - temperature at which alarm kicks in (my model has a res panel light, not function to connect to external sounder etc without a hack, not sure if even possible)
ArU - Autotune. 0000 is off. 0001 is on.
P - proportional band
I - Integral time
D - Derivative time
Ar - anti reset windup
R - heat side proportioning cycle
Sc - temperature sensor calibration (degrees C)
LcK - the lock on settings...
The above are all explained somewhere on wikipedia, so I will gloss over them...
The lock function is the just the pits. There are essential settings that need to be changed and they dont tell you the right codes. Easiest thing to remember - 1000 is 'god' mode, ie you can do anything. 0000 locks everything except the set value.
When you change LcK to 1000, exit settings menu, and press and hold shift and Set for 5 seconds. The screen pops up with Cod. On the top and 0000 on the bottom. Pressing set will scroll though the first set of options. Changing the value below to 0001 then pressing set will scroll through second set of options. These are the 2 'secret' menus.
The first set of options (cod set to 0000) are all SL1.. SL2 etc. the two that are of greatest interest are Sl1 and sl2. These are for the sensor type (pt100 ended up being set to 1000.) and temperature scale (in case you want to switch to farenheit).
The second set of options (cod set to 0001) are as follows.
SLH - set limiter high, the upper reading your sensor can detect
SLL - set limiter low the lowest reading it detects. I am not sur, but i think setting these right makes a difference to the accuracy and consistency of the readings. Dont quote me, but it got loads better after i adjusted these...
PGdP- number of decimal places, note not all sensors support decimal places
oH. Differential gap setting - still not sure what this does?
AH1 - alarm hysteresis - the number of degrees the pv has to drop below alarm level to switch off
dF - digital filtering. This is a terrible feature. It has a purpose of change the pv to match the sv, if its close. THIS MAKES THE PID TELL YOU LIES, SWITCH IT OFF (0000) AND LEAVE IT OFF!!!!!!
So those are the settings.....
Now, once you have set up the unit, made tweaks, changed sensor type etc etc, its time to calibrate, using real world physical processes. I asked my dad, who is a retired physics teacher, and for the level of accuracy we will achieve with our gear, he reckons we will be ok.
Calibrating to steam.
This test involves heating water to boiling in a conical flask on the hob. The sensors are dangled in the middle of the flask, and as the air is driven off by steam, the temperature will stabilise around 100 deg C
Go into your setting menu (hold set for 2 seconds) and click though to sc. this is the offset for how far the reading you get is from 100 degrees c. I have to adjust mine by around - 8deg c.
Now, when this is set, get some ice from the freezer, and level in a glass till most of it is melted. Due to the ice absorbing heat from the water, the water is always kept at just about melting temp, or 0 deg C. Make sure the sensor is floating in the water but not touching the ice, which will actually be colder than 0 deg C.
If you've got it right, the water should read around zero...
Result!
If boiling and freezing point are accurately set, then all temperature in between should be pretty darn close. Now you can mash with confidence!
I hope this helps you all. However the is one final step! Go into settings and set LCK to 0000, so the only changeable value is the set value, we don't want to go and mess up all our work, do we?
