Wiring for pushbutton DINS for alarm reset

[arusinas]

So i'm looking to wire in a momentary push button to aknowledge a BCS alarm. I'm currently getting stuck on the voltage/amperage piece. I was wondering if i could pick everyones brains for ideas.

This is what i have so far:

120VAC wired into pushbutton (NO contactor)
120VAC wired from pushbutton to doorbell transformer resulting in 12VAC
12VAC wired from doorbell transformer to stepdown inverter resulting in +5VDC @ 1amp (same inverter KAL uses in The Electric Brewery build)

now where i'm getting stuck is the BCS specifies that the DINS can handle 5VDC and 300mA, so my resulting amperage could potentially fry the BCS, right? how would you get around this obstacle? suggestions?

[JonW]

It's fairly simple to setup, but there are several steps you need to do to use an external alarm with a reset button on the BCS. You may have some of this done already, but I'll just outline it here anyways for others to see.

Setup Options
- Go to the "System Settings" page and check the option under "Miscellaneous System Settings" titled "Force Alarm to Reg10". This will cause the BCS to assert register #10 any time the alarm should be on. When Reg10 is on, the alarm is on. When Reg10 is off, the alarm is off.

Wiring Input & Output
- You will then need to select an unused BCS output that will drive your alarm. You will usually use this output to drive a relay, which in turn triggers your alarm to activate.
- You will then need to also select an unused BCS input to use as the alarm reset button. You will want to use a normally open (NO) push button switch that is wired between a +5V terminal on the BCS and the input you chose to use.

Ladder Logic
- The first piece of ladder logic needed is to tell your alarm output to go on whenever Reg10 is on. In my case, I used Out15, so the ladder logic shown below (Rung4) is what ties toggling the output with toggling Reg10. Basically, any time Reg10 activates, then the output activates.
- The second piece of ladder logic you need is to tell the BCS to clear Reg10 whenever it see's closure on the input circuit (alarm reset button). In my case, I used Din0 as shown in the ladder logic below on Rung5.

Reg10.JPG (18.51 KiB) Viewed 8646 times

Once these items are setup, you can go to "Edit Processes" and "Miscellaneous State Properties" and set the "Alarm" option to notify you when the state changes. Instead of using the internal speaker beep, it will instead trigger your external alarm.

I use this all the time for state changes that require my attention (like changing a flow rate on a valve). I also use this to alert me for all my hop additions.

[arusinas]

so what do i do when i want to assert the alarm for different things in different states? ie. in state 0 i want to assert the alarm when when my kettle temp reaches its setpoint, but then in state 2 i want to assert the alarm when the timer has reached 0? when editing a process what do i write next to the reg10 section?

[JonW]

You don't need to write anything next to the Reg10 section in the states. That is already done globally in the "System Settings" option I outlined.

When you want the alarm to be on (in any state), you just use the "Alarm' option under "Miscellaneous State Properties" in each state.

Once you do the setup options and ladder logic I outlined, all built in alarm options are directed to the hardware alarm.

[arusinas]

pardon my ignorance, but then how does the BCS know what to alarm on? for example if you have a temperature setpoint (lets say mash out temp) as well as a timer countdown (mash out timer) in a single state, how would it know when it should alarm? or how would i tell it to alarm on the timer, but not the temperature setpoint? p.s. JonW thanks for all the help and also for opening up your BCS to everyone on HBT, its been a great help.

[JonW]

Alarms don't trigger on setpoints or timers, they trigger on state exit. Within the "Edit Process" screen, for a given state, you tell it whether or not to use the alarm. When that state exits (usually because of a setpoint or timer condition), then the alarm activates.

Here's an example: In my process "MLT Heat/Hold", I have the BCS heat my strike water to a specified temperature. Once it hits that temp, it jumps states to a "Hold" state to maintain that temp until I am ready to mash in. The act of changing from State 1 to State 2 (going from "Heat" to "Hold") is what triggers the alarm to let me know I'm ready for mashing in.

The BCS is capable of maintaining the temperature and stopping heating at the setpoint without changing states, but I do it as a 2 state process so that it does cause a state transition to activate the alarm and to simultaneously kick off my process "HLT Heat/Hold" for my hot liquor tank.

You must have a state transition to activate the alarm (and to spawn or kill other processes as I described above).

[arusinas]

aaahhh gotcha, now its clear. Yeah i was looking at your BCS programming as a guest user last night. It helped me with a few things but i just wasnt getting the alarm part. Now it makes sense. Thanks for the help!

[ddorsett]

This is not working for me (462, firmware 3.6.0). I have OUT17 wired to a relay to a buzzer, manual toggle of OUT17 sounds the buzzer.
have the Force Alarm to Reg10 setting checked
ladder logic to connect reg10 (NO) to Out17 (NO) - like the first rung in this thread, although I do not see a continuous solid line from the 1st contact to the output, which seems weird).
I wrote a simple 2 state process both with exit conditions on a 5 sec countdown, first one sets the alarm on state exit, second one clears it.
From the WebUI, I see and hear the alarm. Nothing from the buzzer.
With the ladder logic in place, OUT17 only triggers briefly in manual mode.

What am I missing??

[JonW]

You need the solid line between the contacts to complete the logic circuit. Drag the NC wire from the right panel and fill in each box on the rung. Then click each connector between the boxes until you have the solid line between them.

A picture of your ladder logic would help.

[ddorsett]

With the contact lines through the rung, still no joy (had played with that already).
Alarm rings in browser, no buzzer. Buzzer (OUT17) can only be triggered in manual mode if the ladder logic above is deleted.
Modifying the process to both trigger the alarm and turn on OUT17 turns on and off the buzzer just fine (not an electrical issue).

Here's a screencap of the ladder logic:

alarm-ladder.png (9.09 KiB) Viewed 8363 times

I've also attached my system settings and the test process I'm using to trigger the alarm (which I head just fine in the browser).