Watlow CLS200 - Manual (Page 54)

Chapter 2: Installation CLS200 Series User’s Guide
38 Watlow Anafaze Doc.# 0600-3050-2000
Figure 2.24 Output Connections Using
External 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 in order to determine if the controller
is powered and operational. Do not exceed 5V
Î (dc), 10
mA Î (dc) rating for the watchdog output. The output is low
(on) when the microprocessor is operating; when it stops
operating, the output goes high (off).
Figure 2.25 and Figure 2.26 show the recommended circuit
for the watchdog timer output for the TB50 and the TB18.
Figure 2.25 TB50 Watchdog Timer Output
Figure 2.26 TB18 Watchdog Timer Output
Digital Inputs
All digital inputs are transistor-transistor logic (TTL) level
inputs referenced to control common and the internal +5V
power supply of the CLS200.
When an input is connected to the controller common, the
input is considered on. Otherwise, the input is considered
Heat Output
Cool Output
Alarm Output
Common
+ -
SSR TB50 or TB18
- PS +
+ -
SSR
+ -
SSR
SSR
+ 5V Î (dc)
Watchdog Timer
(Terminal 1)
(Terminal 6)
TB50
+
-
SSR
+ 5V Î (dc)
Watchdog Timer
(Terminal 1)
(Terminal 3)
TB18
+
-