This is caused by the Web Server in the WebBrick rebooting.  The Web Server will do this for two reasons (or more accurately the same reason twice).

1. A brown-out or blip in the 12V power supply, the Web Server has a higher detection threshold than the Process Control Chip and will reboot on shorter brown-outs.
2. (similar to (1)) Overloading the 5V supply to the temperature sensors.  The Web Server is driven from the same 5V bus.
3. Noise on the 5V supply to the temperature sensors - most likely to be caused by improper use of the twisted pair on CAT5E

What do to,

1. Power cycle the WebBrick [brute force approach]
2. Login and issue the manual command RS [Neater approach]
3. If you have a WebBrick Gateway (onetime codename "HGA") do nothing, the WebBrick Gateway will fix the issue overnight

 Here's the example screenshot:

Hi Andy Are the mimics powered by the same power supply as this might be the cause???

Alex

The WebBrick takes in a 12V supply and drops it to 5V using an efficient switch mode circuit.  The 5V is then distributed to:

1. Process Control Chip
2. WebServer Chip
3. Real Time Clock Chip
4. 5V out for temperature sensors (6.4 has a current limiting filter, 6.3 hasn't)
   

The mimics are driven from the Process Control Chip.  In 6.3 this is a direct connection with only EMC suppression.  If you short the Mimic outputs to ground then you could cause the problem as above.  Any long term shorts could over heat and damage the WebBrick.

In version 6.4 we've used a driver chip to decouple the Process Chip.  In this case shorts may cause the 5V to sag.  On the 6.4 there is a possibility to use mimics from the 12V supply.

 In all cases please avoid shorts and general power supply abuse!
 

Yes Andy copy you loud and clear about power supply abuse but I am just wondering if the switches being used (se Link) are drawing to much current and causing this problem

http://www.bulgin.co.uk/PDFs/CatNo82/CatNo82pages/Page_183_2005_Cat.pdf

Alex

 Alex, and any other readers of the thread.

These switches are beyond fine and well into the excellent zone.  You should be able to drive three of these per WebBrick Monitor (6.3)  and five on a 6.4 series. [quick thought -- you are including the 330R series resistor with the mimics?]

Power supply abuse normally comes from wiring the WebBricks 'live' which is what many installers do because the voltages are so low.  Imagine that you brush an earth against the 5V out or any of the DigOuts or monitors.  You quite often see the effect (well I do when I go on site).   WebBricks are protected against normal abuse but not against gratuitous violence.

Regards

Andy

P.S. I really like the Bulgin series, expensive though they are, they are decoratively gorgeous!  If you talk to a chap called Guy Reece he can get all sorts of buttons.