Davicom Cortex units have Up/Down Counters that can be used in a wide variety of applications to keep track of event counts, event rates (counts per day) or to take action based on predefined count limits.
For example, a counter could be used to record the number of times that:
- A site antenna tower has been hit by lightning (requires Davicom’s dedicated lightning strike detector).
- A UPS has tripped.
- A generator has attempted to start.
- A device has been rebooted or power cycled.
- A vehicle has passed through a gate.
- A door has been opened or closed.
- A radio PTT has been activated.
- An HVAC unit has started/stopped during the past 24 hours
Any event or action that can be monitored with a sensor providing either a high/low signal, a contact closure, or an SNMP value, can be used as a trigger or reset signal for a counter. It is also possible to use physical and virtual I/O’s from the Cortex itself.
Up/Down Counter Block Diagram
Up/Down Counter Configuration
The Cortex Up/Down counter Configuration settings and their descriptions are shown below.
1 – ID
ID of the selected counter input. Select one of 32 counters from the drop-down menu.
2 – I/O DESCRIPTION RETRIEVAL
Click the button to retrieve and display the current normal description of that ID. Normally hidden to minimize data transfers on low speed or high fee data connections.
3 – ACTION TYPE
Selects the action type that will happen when an out-of-limit condition occurs. 3 types are available: Major alarm, Minor alarm, and Command (CMD). On CMD, no alarms will be triggered. Use CMD when you want to initiate an action without triggering any alarms.
4 – QUALIFIER
Qualifying element (operand) which can be any input, output, flag, timer, SNMP GET, Logic Gate, etc. Essentially any ID in the Cortex can be used to mute or unmute the input to prevent it from initiating action. When the Qualifier is active, the input will be monitored and be able to generate alarms. When the qualifier is non-active (or normal), the input will be muted and it will not be able to generate an alarm. To invert the Qualifier’s level, simply put a ! in front of its ID. For example, use !1D01 to invert it. Leave the Qualifier field blank for a “don’t care” condition.
5 – QUALIFIER MODE
STATE (default setting): the State (Normal or Active) of the input being qualified can change only when the Qualifier is active. Readings from the input (Current Value) continue to be updated periodically independently from the Qualifier state.
DATA: Same as the STATE mode, but in this case the readings from the input (Current Value) remain frozen at their latest values, as long as the Qualifier is not active. This mode is used like a “Sample-and-Hold” for the readings from the input.
6 – MAXIMUM VALUE
Maximum high count value that the counter can reach. The counter will never go above this value, even if it keeps being triggered by a Count Up Tigger signal. Value must be contained between -2147483648 and 2147483647, and 0 is not allowed. Default value is 10. The Maximum value must be higher than the Minimum value (see below).
7 – MINIMUM VALUE
Minimum low count value that the counter can reach. The counter will never go below this value, even if it keeps being triggered by a Count Down Trigger signal. Value must be contained between -2147483648 and 2147483647. Default is 0. The Minimum value must be lower than the Maximum value (see above).
8 – INITIAL VALUE
Initial value that counter uses when it counts for the first time or after a Reset. Default value is 0.
9 – CONTROLLED OUTPUT
Outputs to be controlled (on/off) based on the state of this input. The two output types allowed are relays (both physical and virtual) and SNMP SETs. For the relays, adding a P suffix will Pulse the relay (ex: 1R01P), L will Latch it and R will Release it.
10 – HIGH LIMIT
High count value above which the counter state will switch from normal to active. For example, if High Limit is set to 3, Counter output will become active on the 3 to 4 count.
11 – LOW LIMIT
Low count value below which the counter state will switch from normal to active.
12 – ENABLE
Enable / disable the counter. Useful to deactivate a counter without losing its settings whenever it must temporarily be disabled for various reasons (ex: intermittent problems, nuisance alarms, system debugging).
13 – SYSTEM LOG
Log the counter’s Alarm or Return-to-normal activity in the System Log. Can be disabled when inputs do not need to be logged, but are required for day-to-day operation.
14 – COUNT UP TRIGGER
ID of I/O used to increase the count value. The counter is increased by a count every time that this I/O becomes active. Counts on the rising edge.
15 – COUNT DOWN TRIGGER
ID of I/O used to decrease the count value. The counter subtracts (decreases) a count every time that this I/O becomes active. Counts on the rising edge.
16 – RESET TRIGGER
ID of I/O to reset the counter. The counter resets when the I/O becomes active. Resets on the rising edge.
17 – RESET
Manually reset the counter.
18 – SIGNALLING ON – ALARM
Enables / disables alarming. When checked, any out-of-limit condition will automatically generate an alarm. When unchecked, no alarm will be triggered when an out-of-limit condition occurs.
19 – SIGNALLING ON – RETURN TO NORMAL
Enables / disables Return To Normal signaling. When checked, a notification will be generated when the input changes back to its normal state after an out-of-limit alarm condition. When unchecked, no notification will be sent when the initial alarm condition returns to normal.
20 – REFRESH / READ
Refresh / read the screen content.
21 – SAVE / WRITE
Save the screen content.
22 – EXIT
Exit menu.
Application Example
Below is a simple example of an application where a Cortex counter could be used.
Say a site is equipped with two power generators, one being the Master and the other being the Backup. When the Master generator is triggered to start, it has to start within 3 tries, otherwise the Backup generator must be started.
The drawing below represents a possible setup for this scenario.
The following inputs and outputs are required from the Cortex:
- Up/Down Counter
- Status Input
- Relay
From the previous image, we see that a logic feedback from the Master generator is fed into the Status Input to monitor the generator run state. A physical relay controls the Backup generator start input. Lastly, a Counter monitors the number of times that the Master generator is attempted to be started, and will activate the Backup start relay when its count value reaches more than 3.
The Cortex Counter configuration screen would look like the one below.
The Counter value can be displayed in a workspace if desired. This is achieved by editing the property of the Workspace element ID box, and changing the Label from Description to Value, as seen below.
See the Workspace setup and configuration articles for more details.
