Watlow PM LEGACY™ Limit Controller  •  12  •  Chapter 1 Overview
PM LEGACY™ Limit All Models System Diagram
(No communications options 2, 3, 5 or 6)
Universal Sensor Input, Configuration Communications, 
Red/Green 7-Segment Display
            Analog Input 1 
Off, Thermocouple, RTD (100Ω, 1kΩ), 
Thermistor (5kΩ, 10kΩ, 20kΩ, 40kΩ), 
Process (V, mV, mA, 1k potentiometer)
Output Status 
Indicators
5
6
1
3
2
4
  Zone
Address
Indicators
  Channel
 Indicates Zone 
Address & Channel*
Indicates I/O
Status
* Channel indicator available
  on PM4/8/9 only
Note:
  Number of inputs and outputs and various combinations of the same will vary
  depending upon part number; see ordering matrix for more detail.
Supervisory 
& 
Power 
Board
Slot C
Limit
Controller 
Board 
Slot A
EZ-ZONE™ PM Limit Controller
Input
Functions
Output
Functions
              Network
Remote User Interface 
Personal Computer 
Programmable Logic Controller
Human Machine Interface
None
Limit reset
Loop & alarms off
Silence alarm
Force Alarm
Lock keypad
Restore user settings
Input Sensor
  EIA 485 Communications 
Standard Bus, Modbus RTU (optional)
           Function Key 
(Not available on 1/32 DIN)
     Programmable Functions
Digital Input (or Output) 5 & 6 
(optional) none, switch, volts dc
             Output 2 
Form A mechanical (5 A) relay
                 Output 1 
None, Switched dc/open collector, 
Form C mechanical (5 A) relay
Off, Limit, 
Alarm
Digital Output (or Input) 5 & 6
    (optional) None, Switched dc
Off, 
Alarm
Limit