Hello all,

I'm a broadcast graphics supplier and I need to implement timing for a sportscompetition which will be broadcasted on tv, but I'm facing some issues and I hope I can find some answers here.


I was able to loan a CP540 and some photocells and transmitters and receivers.

I have everything hooked up together and when I physically test the photocells, they are working. When I interrupt the beam of the photocells, the signal is sent up to the reciever. So that's all working fine.

On the CP540-side I am able to connect to the ChronoPrinter and I receive data when I use the manual test-buttons 1 -> 4. However, it seems I am not getting any data from the receiver.

I have two photocells, one for start and one for finish, which are arriving at port 1 and 2 on the Receiver-side.

I have read the manual of the CP540 and I saw that I have to connect start and finish on port 1 and 4 because ports 2 and 3 are used for intermediate timing.


So I have connected Port 1 and 2 of the receiver to Port 1 and 4 of the CP540, but this is not triggering the CP540. Does anybody know what I'm doing wrong?

I have attached a picture of the cabling between the receiver and the CP540.


I also have a second, related question. I was thinking that my issue might have to do something with the Timing Mode and with the fact if i'm in a Run or not.

Now, for my use, I don't use the CP540 for actual timing or ranking. I only use it's time of day. So the information I'm interested in, is when the start-cell was interrupted and when the subsequent finish-cell was interrupted. Which is essentially the information I get when I use the 1 > 4 testbuttons.

So in my software I select the competitor and then when the start-cell is interrupted, I add the received time from the CP540 in my database. When the competitor passes the finishline I repeat the same thing. I activate the competitor and the received time of the CP540 will be added to my database and the difference will be calculated.

Does anybody know which Timingmode I have to use for this?


A third (and last) question; The CP540 is supposed to be a very accurate timing device. Is there any way that I can sync my pc-clock to the internal timing of the CP540 so I can use it as a sort of Master Clock?


Thank you,



Photos (1)
Original Post

Okay, so I have managed to find the issue.

I had to "unblock" the inputs using the orange buttons underneath the testbuttons 1 > 4. I actually thought these were led's so I didn't press them yet.

So problem solved!

And with that I also received the correct format for the data as well, so 2 of the three questions have been solved.

If anybody know the solution to the last question, syncing my pc with the CP540.




The thrust of your third question is a little unclear (to me, anyway). I think you're asking either (a) if you can use the PC clock as a time base for timing software, or (b) if you can use the CP 540 to update the PC clock for improved accuracy. 

(a) No - PC clock not accurate enough for timing. Use the CP 540, that is what is was designed for.

(b) Maybe - but there are easier ways like any number of apps that update to established online time base signals like www.time.is

Windows 10 and probably most other semi-current OS have the option to automatically update PC time from central time base.



Thanks Slykarma for your response.

I was indeed referring to option B. Synchronize my PC-time with the time of the CP540. I'll explain a bit more in detail why I'm asking this.

In my software I'm always receiving triggers from the CP540. Everytime someone passes through the beam the trigger is received and is stored in the memory.

Only when I "activate" the trigger there will be an action assigned to it.

Now in some events I have participants that start at a specific, known, time. In that case I would like to have the trigger activated automatically. So for example, if an athlete will start at 10:05:00 I want to activate the trigger automatically at 10:04:55. However, this will only work ofcourse if the time of the PC is the same as the time of the CP540. So thats wht I would like to synchronize my PC-time with the CP540-time.


You still have the same problem as option (a): you're asking the PC clock to be as accurate as the timer. And of course for short periods, it will be, but we know there will be drift between the timer and PC clock. You could re-sync the two periodically, but doing so within the event would mean varying degrees of dissimilarity between timer and PC clock across the various results. 

I'm not sure why you'd want to trigger an event manually when you just wait for an athlete to create an impulse by starting or finishing, but there must be a reason or you wouldn't be asking here. In cycling, time trial start lists post a start time in hh:mm:ss for each athlete, but we don't assume they started on time and just record TOD for their finish and calculate the difference. No, we take exact TOD of both start and finish. Group start events like road race or XC, we still take an exact TOD of start rather than banging in the scheduled one.


Are you involved in equestrian events? The Al Shaqab lanyard in the background led me to that question.

The tape says Start-Finish rather than Jumping. Are you involved in Endurance?

We have several associates in the software business who use TAG Heuer CP 540 and CP 545 timers for equestrian applications on a regular basis. Using the CP timers as a time base and then calculating a smooth running time using the PC is a bit complicated as you have discovered.

Feel free to contact us at info@protimingsolutions.com if you would like to discuss this privately.






Add Reply

Likes (0)