Measurement Computing TempScan/1100 - Manual (Page 78)

4-20 System Configuration 879596 TempScan / MultiScan User's Manual
For example, let us assume a channel has alarm setpoints of 100 and -100, and a hysteresis of 10. If 100 is
exceeded, the channel will remain in the alarm state until the signal falls below 90. Or if -100 is exceeded,
the channel will remain in the alarm state until the signal rises above -90.
Digital Alarm Outputs
If preferred, an alarm event for a specific channel can be used as a stimulus for a digital (TTL) output
signal. In turn, this signal can be used to set off an audible alarm (user-supplied) or to communicate to
another device that the alarm state has occurred.
Thirty-two (32) digital alarm outputs are available via the TempScan/1100 or MultiScan/1200 rear-panel
DB50 connector. Although analog input channels on the Exp/10A or Exp/11A expansion unit can be used
to stimulate alarms, neither of these expansion units provides digital alarm outputs. Consequently,
regardless of the number of connected expansion units, the TempScan/1100 or MultiScan/1200 system can
only provide 32 digital alarm outputs.
You can assign as many alarm states as you prefer to any digital output. To configure alarm conditions for
driving the digital output lines, use the Configure Channels (
C ) and Assign Digital Alarm Output ( A )
commands. The former command determines the high setpoint, low setpoint and hysteresis of the alarm
state, while the latter command assigns alarm states of a particular channel, or range of channels, to
individual outputs of the 32 available digital alarm outputs.
Example 12b. TempScan/1100 Digital Alarm Output
(1) PRINT #1 “OUTPUT07: C1-32, 1, -1000.0, +1000.0, 10.0X”
(2) PRINT #1 “OUTPUT07: A1, 1X”
(3) PRINT #1 “OUTPUT07: A2, 2X”
(4) PRINT #1 “OUTPUT07: A3, 2X”
The above program example demonstrates how to configure alarms and associate them with digital alarm
outputs for 32 channels of the TempScan/1100:
• Line 1: Setup channels 1 to 32 with Type J thermocouples, low setpoint = -1000.0 °C, high setpoint =
+1000.0 °C, and hysteresis = 10.0°C.
• Line 2: Assign alarm channel 1 to digital output 1.
• Line 3: Assign alarm channel 2 to digital output 2.
• Line 4: Assign alarm channel 3 to digital output 2. So Channel 2 or 3 can set digital output 2.
Example 12c. MultiScan/1200 Digital Alarm Output
(1) PRINT #1 “OUTPUT07: C1-24, 1, -500.0, +500.0, 50.0X”
(2) PRINT #1 “OUTPUT07: A1, 1X”
(3) PRINT #1 “OUTPUT07: A2, 2X”
(4) PRINT #1 “OUTPUT07: A3, 2X”
The above program example demonstrates how to configure alarms and associate them with digital alarm
outputs for 24 channels of the MultiScan/1200:
• Line 1: Setup channels 1 to 24 with Type J thermocouples, low setpoint = -500.0 °C, high setpoint =
+500.0 °C, and hysteresis = 50.0°C.
• Line 2: Assign alarm channel 1 to digital output 1.
• Line 3: Assign alarm channel 2 to digital output 2.
• Line 4: Assign alarm channel 3 to digital output 2. With both Lines 3 and 4, either channel 2 or 3 can
set digital output 2.