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[SOLVED] Fan control - NZXT Cam

Apr 7, 2020
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Hello,
Case NZXT H710i
I have just built my first PC, and for the most part, I am an idiot, as the name suggests.
When the case arrived the 4 NZXT fans were pre installed. 3 in the front and one rear exhaust.
I believe:
The 3 fans at the front were already connected to the came.
Each connection to the cam was a 'daisy chain' cable.
I had bought 3 additional fans - ll120 Corsair fans.
I had connected the RGB cables into the node as per instructions, and then, instead of installing each fan into a header on the board (Asus Crosshair Hero VIII) which would cause hassle with cable routing ect, I utilised the the daisy chains ( each daisy chain only had one 4 pin, the others had the 3rd pin missing).
I also plugged the rear fan into one of these daisy chains.
RGB on the corsairs work and all 4 (the one rear exhaust NZXT fan and the 3 corsair fans) spin.
But they do not appear in the CAM software.

Questions:
Should they show in the CAM software.
Have I connected this all up correctly.
How do I adjust fan speed.

Thanks in advance.
 

Paperdoc

Glorious
Ambassador
Lets' start with the differences between 3- and 4-pin fans. BOTH can have their speed controlled, but that requires different methods.

For a 3-pin fan, the signals on the mobo header pins and the standard fan wire colours are:
Pin #1 - BLACK - Ground
Pin#2 - RED - +VDC power ranging from 12 VDC max speed down to 5 VDC - less may allow the fan to stall
Pin #3 - YELLOW - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Regardless of how the mobo header decides what the fan speed should be, the mobo accomplishes control of the fan speed by varying the voltage sent out on pin #3. That is called Voltage Control Mode (aka DC Mode) of fan speed.

For a 4-pin fan the wire colours are different; the electrical signals are similar in most cases but the differences are important.
Pin #1 - Ground
Pin#2 - +VDC power constantly 12 VDC
Pin #3 - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Pin #4 - PWM (Pulse Width Modulation) signal. This is a signal in the 20kHz frequency range that is similar to a classic Square Wave in that it is either fully on or fully off. What is special, though, is that the time the wave is "On" is NOT always 50% as it is in a square wave. The "%On" value can be changed. Inside the motor case there is a small chip that uses this signal to switch the power from the 12 VDC line to the motor windings on and off VERY rapidly, effectively changing the average time the motor gets power, and hence altering its speed. (By the way, this is not how industrial motor PWM speed controls operate, but that is irrelevant here.)
The mobo controls the speed of the fan by varying the PWM signal sent out on Pin #4. That is called PWM Mode of speed control.

On a mobo, any 3-pin fan header can only use the older Voltage Control Mode, since it cannot send out a PWM signal with no Pin #4. Today almost all fan headers on mobos have 4 pins and CAN do PWM Mode. BUT they also CAN do the older Voltage Control Mode simply by not sending out any signal on Pin #4 and varying the Voltage on Pin #2. In the configuration options of most mobo header you are given a choice of which Mode this header will use, and that ought to be set according the the type of fan you have plugged into it. If you make the header signal Mode match the fan type (3-pin or 4-pin), the fan motor's speed WILL be controlled.

When you connect more than one fan to a single header (or one port of the Smart Device you have), all of them receives the same signals and does exactly the same thing.. As I said above, one small note is that the header cannot deal with pulse signals for speed coming at it from more than one fan, so the cables from that port to each fan are set up with Pin #3 available on ONLY one output connector. That has no effect on fan speed. It does impact ability of a fan header to detect FAILURE of a fan from lack of a speed signal when SOME of the fans never report their speed.

If I understand correctly, you have added extra fans merely by plugging them each into the outputs of a daisy-chaing connector system on each of the original fans supplied with the case. I would presume that the way the original fans are wired is that each fo those sends its own speed back to the source (port on the Smart Device) but does NOT send back the speed of any fan plugged into its daisy-chain output. So what CAM can show you is the speed of the three original fans plugged into the Smart Device's three ports, but not of an others.
 

Paperdoc

Glorious
Ambassador
Two items to check. First, an explanation.

Any fan header can deal with the speed signal coming back to it from ONE fan only. So when devices like Splitters are used, only ONE of the output connectors has all 4 pins, and the others are missing Pin #3. Only the speed of the fan connected to the 4-pin output is sent back for reading and display. Now, on the Smart Device V2 that is mounted in your case, it has three output ports, each with a sort of Splitter cable that can feed up to three fans. I suspect that each port of the Smart Device acts like a mobo header so that each can report the speed of ONE fan connected to it via the supplied cables. Thus, you must ensure that there IS a fan plugged into each of the 4-pin output connectors that you are using. Only those fans' speeds can be "seen" and reported by any tool.

The other item is HOW the CAM software can get its info. In the case manual if you look closely at the diagram of that Smart Device V2 item, you will seee at its lower right two cables marked Power / USB are supposed to come out of the Device. The Power cable ends in a wide connector that plugs into a SATA power output from the PSU to provide power to the Device and its fans. The USB cable ends in a different connector that must plug into a USB2 header on your mobo. That is the means by which the CAM software can communicate with the Smart Device to read its info and issue control instructions. If that cable is not connected, CAM can do almost nothing.
 
Reactions: mctrader07
Apr 7, 2020
28
0
30
0
Two items to check. First, an explanation.

Any fan header can deal with the speed signal coming back to it from ONE fan only. So when devices like Splitters are used, only ONE of the output connectors has all 4 pins, and the others are missing Pin #3. Only the speed of the fan connected to the 4-pin output is sent back for reading and display. Now, on the Smart Device V2 that is mounted in your case, it has three output ports, each with a sort of Splitter cable that can feed up to three fans. I suspect that each port of the Smart Device acts like a mobo header so that each can report the speed of ONE fan connected to it via the supplied cables. Thus, you must ensure that there IS a fan plugged into each of the 4-pin output connectors that you are using. Only those fans' speeds can be "seen" and reported by any tool.

The other item is HOW the CAM software can get its info. In the case manual if you look closely at the diagram of that Smart Device V2 item, you will seee at its lower right two cables marked Power / USB are supposed to come out of the Device. The Power cable ends in a wide connector that plugs into a SATA power output from the PSU to provide power to the Device and its fans. The USB cable ends in a different connector that must plug into a USB2 header on your mobo. That is the means by which the CAM software can communicate with the Smart Device to read its info and issue control instructions. If that cable is not connected, CAM can do almost nothing.
Thank you for a respone.

I was considering the facts that only 3 will display on the cam and fan speeds set to that fan would affect all fans connected via the daisy chain, which is what youre confirming?

I currently have a fan curve of 50% until 45degrees and the 100% onwards. I am aware of ruining the bearings and, ofcourse, sounds, but honestly, it does not bother me. Ive got some spare noctua's doing nothing that could be used to replace and I want the system as cool as possible.

The cam is plugged in with a sata and then on to the board with the USB2

To confirm, for my small brain to comprehend, the 3 pins are....what the fan needs to spin, and the 4th enables control through the software? So there has to be a 4pin to control? or am I not understanding.

Thanks.
 

Paperdoc

Glorious
Ambassador
Lets' start with the differences between 3- and 4-pin fans. BOTH can have their speed controlled, but that requires different methods.

For a 3-pin fan, the signals on the mobo header pins and the standard fan wire colours are:
Pin #1 - BLACK - Ground
Pin#2 - RED - +VDC power ranging from 12 VDC max speed down to 5 VDC - less may allow the fan to stall
Pin #3 - YELLOW - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Regardless of how the mobo header decides what the fan speed should be, the mobo accomplishes control of the fan speed by varying the voltage sent out on pin #3. That is called Voltage Control Mode (aka DC Mode) of fan speed.

For a 4-pin fan the wire colours are different; the electrical signals are similar in most cases but the differences are important.
Pin #1 - Ground
Pin#2 - +VDC power constantly 12 VDC
Pin #3 - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Pin #4 - PWM (Pulse Width Modulation) signal. This is a signal in the 20kHz frequency range that is similar to a classic Square Wave in that it is either fully on or fully off. What is special, though, is that the time the wave is "On" is NOT always 50% as it is in a square wave. The "%On" value can be changed. Inside the motor case there is a small chip that uses this signal to switch the power from the 12 VDC line to the motor windings on and off VERY rapidly, effectively changing the average time the motor gets power, and hence altering its speed. (By the way, this is not how industrial motor PWM speed controls operate, but that is irrelevant here.)
The mobo controls the speed of the fan by varying the PWM signal sent out on Pin #4. That is called PWM Mode of speed control.

On a mobo, any 3-pin fan header can only use the older Voltage Control Mode, since it cannot send out a PWM signal with no Pin #4. Today almost all fan headers on mobos have 4 pins and CAN do PWM Mode. BUT they also CAN do the older Voltage Control Mode simply by not sending out any signal on Pin #4 and varying the Voltage on Pin #2. In the configuration options of most mobo header you are given a choice of which Mode this header will use, and that ought to be set according the the type of fan you have plugged into it. If you make the header signal Mode match the fan type (3-pin or 4-pin), the fan motor's speed WILL be controlled.

When you connect more than one fan to a single header (or one port of the Smart Device you have), all of them receives the same signals and does exactly the same thing.. As I said above, one small note is that the header cannot deal with pulse signals for speed coming at it from more than one fan, so the cables from that port to each fan are set up with Pin #3 available on ONLY one output connector. That has no effect on fan speed. It does impact ability of a fan header to detect FAILURE of a fan from lack of a speed signal when SOME of the fans never report their speed.

If I understand correctly, you have added extra fans merely by plugging them each into the outputs of a daisy-chaing connector system on each of the original fans supplied with the case. I would presume that the way the original fans are wired is that each fo those sends its own speed back to the source (port on the Smart Device) but does NOT send back the speed of any fan plugged into its daisy-chain output. So what CAM can show you is the speed of the three original fans plugged into the Smart Device's three ports, but not of an others.
 
Apr 7, 2020
28
0
30
0
Lets' start with the differences between 3- and 4-pin fans. BOTH can have their speed controlled, but that requires different methods.

For a 3-pin fan, the signals on the mobo header pins and the standard fan wire colours are:
Pin #1 - BLACK - Ground
Pin#2 - RED - +VDC power ranging from 12 VDC max speed down to 5 VDC - less may allow the fan to stall
Pin #3 - YELLOW - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Regardless of how the mobo header decides what the fan speed should be, the mobo accomplishes control of the fan speed by varying the voltage sent out on pin #3. That is called Voltage Control Mode (aka DC Mode) of fan speed.

For a 4-pin fan the wire colours are different; the electrical signals are similar in most cases but the differences are important.
Pin #1 - Ground
Pin#2 - +VDC power constantly 12 VDC
Pin #3 - Fan Speed - a series of 2 pulses per revolution sent by the fan motor back to the mobo header for counting.
Pin #4 - PWM (Pulse Width Modulation) signal. This is a signal in the 20kHz frequency range that is similar to a classic Square Wave in that it is either fully on or fully off. What is special, though, is that the time the wave is "On" is NOT always 50% as it is in a square wave. The "%On" value can be changed. Inside the motor case there is a small chip that uses this signal to switch the power from the 12 VDC line to the motor windings on and off VERY rapidly, effectively changing the average time the motor gets power, and hence altering its speed. (By the way, this is not how industrial motor PWM speed controls operate, but that is irrelevant here.)
The mobo controls the speed of the fan by varying the PWM signal sent out on Pin #4. That is called PWM Mode of speed control.

On a mobo, any 3-pin fan header can only use the older Voltage Control Mode, since it cannot send out a PWM signal with no Pin #4. Today almost all fan headers on mobos have 4 pins and CAN do PWM Mode. BUT they also CAN do the older Voltage Control Mode simply by not sending out any signal on Pin #4 and varying the Voltage on Pin #2. In the configuration options of most mobo header you are given a choice of which Mode this header will use, and that ought to be set according the the type of fan you have plugged into it. If you make the header signal Mode match the fan type (3-pin or 4-pin), the fan motor's speed WILL be controlled.

When you connect more than one fan to a single header (or one port of the Smart Device you have), all of them receives the same signals and does exactly the same thing.. As I said above, one small note is that the header cannot deal with pulse signals for speed coming at it from more than one fan, so the cables from that port to each fan are set up with Pin #3 available on ONLY one output connector. That has no effect on fan speed. It does impact ability of a fan header to detect FAILURE of a fan from lack of a speed signal when SOME of the fans never report their speed.

If I understand correctly, you have added extra fans merely by plugging them each into the outputs of a daisy-chaing connector system on each of the original fans supplied with the case. I would presume that the way the original fans are wired is that each fo those sends its own speed back to the source (port on the Smart Device) but does NOT send back the speed of any fan plugged into its daisy-chain output. So what CAM can show you is the speed of the three original fans plugged into the Smart Device's three ports, but not of an others.
This was amazing. Thank you so much. Hugely detailed and simply put for an idiot like myself.

I have put the fan configuration exactly how you suspected. And as a result, can only see those 3 fans.
What I have done is identified (0% fan speed and see which ones stop) exactly what fans correspond to the 3 fans listed on the CAM software and then renamed the CAM fans accordingly.

Again, thank you so much, great insight.
 

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