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Precision Digital PD138 Minimux® II Temperature & Process Scanner

Minimux® II Temperature & Process Scanner

Scan Most Signals/Sensors 
The Minimux II is a microprocessor-based eight channel analog input scanner/multipexer and annunciator that provides low-cost automatic switching for multi-point display and alarm systems. Each Minimux II can automatically switch up to eight inputs to another device such as a digital panel meter, controller, or PLC. Signal switching is done via reed relays making the Minimux II ideal for switching thermocouples, RTDs, control loops, and AC & DC signals.

Uses for Minimux II:
Automatic Switching - In its most basic form, the PD138 is the electrical equivalent of a double-pole, eight position automatic switch. Whatever input is brought into the PD138 is dwelled on for a certain amount of time while being channeled/switched out to another device. For example, a typical application may involve channeling/switching eight type J thermocouples into a single digital panel meter. 
Temperature Scanning - One of the most popular uses for the PD138 is temperature monitoring, especially the monitoring of bearing and stator winding temperatures. Any of the many different style thermocouples, RTDs, or thermistors can be used with the PD138 - right out of the box. 
Automatic or Manual Scan - The PD138 automatically scans through each active channel, dwells on that channel for an independently programmed dwell time, while at the same time switching the signal to an external device. The scanning can be stopped, or scanned manually via the front panel stop/go pushbutton. 
Alarm Annunciator - One of the key features of the PD138 is its ability to indicate and process alarms that are generated by an external device. Each channel of the Minimux II has an independent ‘Alarm-in’ terminal that allows an external device to trigger an alarm on the Minimux II. The external device may be the relays on a digital panel meter, such as the PD765, or the digital output from a PLC. 
First-out (sequenceF2A) - The PD138 can be configured to recognize first-out alarms. On the PD138, these are one or more alarms that occur during the first complete scan where an alarm is present on one or more channels. self Test When the PD138 is powered, the LEDs are turned on one channel at a time until all green and then all red LEDs have been tested. The internal horn will sound at the end of the LED test.

• 8 inputs per unit, eliminates need for 7 Displays  
• unlimited number of units per system
• free custom Message Labels
• Thermocouples, RTDs, process, AC & DC inputs
• adjustable Dwell Time for each channel
• independent alarm input for each channel
• first-out alarm indication
• alarms indicated by LEDs, Built-in Horn, and relay
• Built-in 85 dB Horn with silence pushbutton
• stop-on-alarmed channel (field select)
• non-interruptible 4-20 mA inputs
• sunlight readable indication
• NEMA 4x/IP65 front  
• shallow Depth 1/8 Din enclosure
• -40 to 65°C operating Temperature range

Select a link under the "item" tab below to order.

Cat #DescriptionsTypeWith Loop ResistorPower
PD138-28 Chan. Temp & Process ScannerMinimux II • Model PD138PD138-2-CL24 VDC
PD138-38 Chan. Temp & Process ScannerMinimux II • Model PD138PD138-3-CL115 VAC
PD138-48 Chan. Temp & Process ScannerMinimux II • Model PD138PD138-4-CL230 VAC
Number Of Channels: 8 double-pole channels per unit
Number Of Channels Per System: Unlimited
Signals Switching: DPST reed relays
Contact Resistance: 0.2 Ω maximum
Maximum Input Voltage: 200 VAC/DC (switched or common mode)
Maximum Current Switched: 0.5 A
Maximum Power Switched: 10 W
Dwell Time: Each channel adjustable from 0.6 to 30 seconds
Non-Volatile Memory: All programming values are stored in non-volatile memory for ten years if power is lost
Scan Method: Internally or manually controlled
Channel Indication: Green LED on front panel
Disabling Channels: Any channel may be disabled
Scan Stop: The scan may be stopped by pressing and holding the STOP/GO button for more than 0.5 seconds. The scan may be resumed by pressing and releasing the STOP/GO button quickly (less than 0.5 seconds)
Alarm Input: Independent alarm input for each channel. Input Impedance; 25 Kohm, typical pull-up to 5 V
Alarm Sequence: Sequence A or Sequence F2A (first out)
Alarm Outputs: 1. Alarm condition indicated by:
Front panel red LED for each channel.
2. Relay, 1 SPDT (form C); rated 2 Amp @ 30 VDC or 2 Amp @ 250 VAC resistive load; 1/14 HP @ 125 / 250 VAC for inductive loads. For failsafe operation, the relay is energized in the non-alarm state. In the case of a power failure, the relay will go to the alarm state, (NC contact is connected to common).
3. Built-in Horn, 85 dB.
4. Stop-on-alarmed-channel (user select)4.
Alarm Acknowledge: Front panel ACK and rear connector terminals
External Switch Functions: The functions of the front panel buttons are available at screw terminals at the rear of the instrument
Message Labels: Free, custom printed, 2 lines per message at 14 characters per line. Factory or field printable. See manual for details.
Connections: Removable screw terminal connectors provided: Power + Relay: 22 to 12 AWG; Alarm Input, Analog Signal, External Switches, I/O: 30 to 16 AWG
Operating Temperature: -40°C to 65°C
Storage Temperature: -40°C to 85°C
Relative Humidity: 0 to 95% non-condensing
Power Options: 115 VAC, ± 10%, 50/60 Hz, 4 VA; 230 VAC, ± 10%, 50/60 Hz, 4 VA; 12-24 VDC (9-18 VAC, 50/60 Hz) 2 W
Led Test: All LEDs are tested on power-up
Enclosure: 1/8 DIN, high impact plastic, UL94V-0
Front Panel: NEMA 4X, panel gasket provided
Weight: 9.9 oz (280 g)
Warranty: 3 years parts and labor

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