Watlow PPC-2000 - Manual (Page 67)

PPC-2000 User’s Guide Chapter 2: Hardware Installation
Doc.# 30002-00 Rev 2.3 Watlow Anafaze 43
Using the CPU Watchdog Signal
The PPC system constantly monitors the functioning of its
microprocessor. The CPU watchdog output is Low (on) when
the microprocessor is operating; when it stops operating, the
output goes High (off). This sink output is available on screw
terminal #48 on the TB50 attached to the PPC-2010 Processor
module.
The figure below shows the recommended circuit for the CPU
Watchdog signal output.
Figure 2.26 Recommended circuitry for CPU
Watchdog
SDAC Connections
Up to 5 Serial Digital to Analog Converter (SDAC) modules can
be connected to digital outputs on the processor module. Each
can provide an analog current or voltage signal.
Single SDAC Systems
Use the +5V output on the PPC-IPS-2 to power SDACs. Use
stranded 18 to 22 gauge wire for most installations. Refer to
Figure 2.27 on page 44 for system setup.
• Connect SDAC Pin 1 to the +5V terminal on the power
supply.
• Connect SDAC Pin 2 to the DC COM terminal on the
power supply.
• If a separate power supply is used, connect the common to
the
DC COM on the PPC-2000 power supply.
• Connect SDAC Pin 3 to the SDAC clock output on the
processor’s TB50 (digital output
46 ).
• Connect SDAC pin 4 to the desired control output on the
TB50 (digital output
41-45 ).
• Connect SDAC pins 5 and 6 to the input of the controlled
device.
SSR
+ 5Vdc
CPU
(pin 48)
PPC-IPS-2
+
-
Monitoring or
Interlocking
Device
Watchdog
TB50