A testing laboratory needs to log critical temperatures on fridges, freezers, water baths and incubators. Further, an alarm needs to be registered to generate a report when any of these temperatures are out of range for a period of time.
Access needs to be by a security code system to change whether the alarm is on or off, and then allow the supervisor to toggle it on and off and prevent further operator access. The operator is not allowed to set the state for security reasons, the supervisor will be the only one allowed to do this. However, the operator will need to see whether alarms are on or off. Datataker provided a solution.
- DeLogger Pro
A mimic screen will display the alarm status and another mimic screen will be used to control whether the alarm is set active or not. Sometimes the sensor is out of order or not in use, so making the alarm non active stops false reports.
The operator will need a mimic panel to display alarms, which are active and non active. As mentioned the operator is not allowed to set the state for security reasons, the supervisor will be the only one allowed to do this.
Using the DT800, with DeLogger Pro
Set up an alarm mimic panel with buttons and LEDs above. The buttons will toggle the alarms on and off, the LEDs will follow the status of the alarm At the bottom of this screen are two further buttons, allowing changes to the status and lock out further changes.
A CV controls the LED colours. When the CV value is -1 the LED is red, when it is +1 it is green. A separate schedule is set up to scan the CVs of these LEDs so the status can be updated after the changes. The CV values are also used to disable or enable the alarms in the schedule that reads them.
For example, ALARM 6 LED is allocated to 330CV. The supervisor clicks on CHANGE. This calls a DeLogger action which asks for a 4 digit security code, in this case the correct code is ‘6146’, default is no entry (‘1000’). The value of 6146 is passed to an internal %2 variable and assigned to 60CV. Two control CV’s 80CV and 70CV are set. If the code is correct, 80CV is set to 1, 70CV to 0.
The Boolean expression in the ‘SEND TEXT’ expression does this. Now clicking on ALARM 6 button sets 330CV to the opposite state by means of the Boolean expression shown. The expression reduces to 330CV= -330CV. Note that if 80CV= 0 and 70CV =1, 330CV would not change. This is, in fact, the normal ‘no change’ state for the alarms when the security code is not entered or wrong. The operator can click away, nothing changes.
The LED’s change colour by triggering the LED display schedule, using a command such as XC, if C is the schedule. This is called by another action command from the button.
The supervisor can now click LOCK and send a default access code of 1000 to the 60CV variable and set 70CV and 80CV to the non-access state. If the supervisor forgets to do this, this command can be embedded under another button, such as one, which selects another mimic panel screen. Another way may be to create a delay such that the access is open for a limited time period.
The same security code system can be used to hide and show particular screens in the project, using DeLogger Pro actions to close or open a screen. In this case, nobody can access the mimic panel while it is not in view. Remember to take the program screen out of the project so that clever people do not find the access code.