Watlow CPC400 - Manual (Page 49)

CPC400 Series User’s Guide Chapter 2: Installation
Doc. 0600-2900-2000 Watlow Anafaze 35
Figure 2.22 Sample Heat, Cool and Alarm Out-
put Connections
Figure 2.23 Output Connections Using Exter-
nal Power Supply
CPU Watchdog Timer
The CPU watchdog timer constantly monitors the micro-
processor. It is a sink output located on TB50 terminal 6 or
TB18 terminal 3. The output can be connected to an exter-
nal circuit or device to monitor whether the controller is
powered and operational. Do not exceed the 5V
Î ( dc), 10
mAdc rating for the watchdog output. The output is on
(low) when the microprocessor is operating; when it stops
operating, the output goes off (high).
Figure 2.24 and Figure 2.25 show the recommended circuit
for the watchdog timer output for the TB50 and the TB18.
Figure 2.24 TB50 Watchdog Timer Output
Figure 2.25 TB18 Watchdog Timer Output
Heat Output
Cool Output
Alarm Output
+5 V Å (ac)
+ -
+ - + -
TB50 or TB18
Solid-State
Relay
Solid-State
Relay
Solid-State
Relay
Heat Output
Cool Output
Alarm Output
Common
+ -
TB50 or TB18
- PS +
+ - + -
Solid-State
Relay
Solid-State
Relay
Solid-State
Relay
Solid-State Relay
+ 5V Î (dc)
Watchdog Timer
(Terminal 1)
(Terminal 6)
TB50
+
-
+ 5V Î (dc)
Watchdog Timer
(Terminal 1)
(Terminal 3)
TB18
+
-
Solid-State Relay