Specifications

ELAN AUDIO - SENTINEL / RCU-01 RCU01R02 PAGE 22/49
7.9 Site Analog Input Configuration
Operation
There are 8 analog inputs available for monitoring, alarming and display under user control on each RCU. Any
individual input can be scaled and can also be configured to generate an alarm. This alarming function can be
disabled if desired.
Analog Input Title ( 12 chars max )
This is used on SENTINEL and on the RCU to provide a meaningful title for the analog input. It is used on the Site
Status window and the Alarm Log window.
Analog Input Units ( 8 chars max )
This is used on SENTINEL and on the RCU to provide a meaningful unit for the analog input. It is used on the Site
Status window and the Alarm Log window.
Alarm Configuration
Each of the analog inputs can be configured to generate an alarm under certain conditions.
• Disabled An analog input will not generate an alarm if the High Alarm Limit is set to the Full Scale value and the
Low Alarm Limit is set to Zero Scale Value. A simple way to ensure that the alarm is disabled is to set the alarm
limits to values outside the scale values. SENTINEL will automatically limit the actual alarms to the scale values.
• High Limit If the Analog input is greater than the High Alarm Limit for longer than the Duration ( 30 Seconds or 3
Minutes ) then an alarm will be generated by the RCU and reported to SENTINEL as soon as possible. Note:
SENTINEL will automatically reverse scale these values from what the user enters to the closest value
when applied to the scaling formula.
• Low Limit If the Analog input is less than the Low Alarm Limit for longer than the Duration ( 30 Seconds or 3
Minutes ) then an alarm will be generated by the RCU and reported to SENTINEL as soon as possible. Note:
SENTINEL will automatically reverse scale these values from what the user enters to the closest value
when applied to the scaling formula.
• Duration ( 30 Sec ) The analog input must be in the alarm condition for greater than thirty seconds before it will
be recognised by the RCU as being in alarm.
• Duration ( 3 Min ) The analog input must be in the alarm condition for greater than three minutes before it will be
recognised by the RCU as being in alarm.
• Enable Logging This enables event logging in the RCU if this input exceeds the alarm thresholds or returns to
normal for greater than 1 second.
Analog Scaling Configuration
To allow for various user input configurations the raw 8 bit ( 0 - 255 ) analog value can be scaled using a full and zero
scale value. Basically the full scale value is equivalent to the maximum raw input value, 255, and the zero scale value
is equivalent to the minimum raw input value, 0.
This scaling information is used in the following formula to scale, or convert, to the users requirements.
The formula is:
Displayed value = ( Actual raw value * ( Full Scale -Zero Scale ) / 255 ) + Zero Scale.
For example if we configured an input to have a full scale value of 1000 and a zero scale value of -1000 then a raw
value of 100 would be displayed as ( 100 * ( 1000 - -1000 ) / 255 ) + -1000 = -215.7
Full Scale This is the value used by SENTINEL and the RCU to set the upper limit for the analog input.
Zero Scale This is the value used by SENTINEL and the RCU to set the lower limit for the analog input.
To avoid fractional values being shown, set the overall scaling to be a factor of 255, 25.5 or 2.55 or multiples of those,
i.e., 510, 51 and 5.1 respectively. This will limit the amount of numbers shown after the decimal point to none, one and
two respectively.
Apply
This function applies the changes back to the configuration database. All changes made since entering the site
configuration window, or since the last 'Apply' will be written to the configuration database.
Note: Any changes applied cannot be undone unless the individually parameter is edited then applied back to the database. This
function does not update the RCU, only the configuration database. ( see Site Configuration )
Report Site Configuration
Generate a report that details the configuration of the RCU