TELEVAC MX2A Instruction Manual

The Fredericks Company

MX2A Active Thermocouple Gauge

Instruction Manual

The Fredericks Company - Televac

2400 Philmont Avenue

Huntingdon Valley, PA 19006

web: www.frederickscompany.com

email: [e-mail]

tel: [phone]

fax: [phone]

CONTENTS LIST OF FIGURES

Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.3 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.4 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2 Electrical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.3 Menu Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.4 Menu Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.5 Explanation of Menu Items and Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.5.1 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.5.2 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.5.3 Set Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.5.4 Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.5.5 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.6 Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3 RS-485 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.1 Changing Communications Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 Communications Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.3 RS-485 Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.4 RS-485 Sample Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.5 RS-485 Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

List of Tables

1 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 RS-485 Communication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3 RS-485 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4 RS-485 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5 Understanding the Sample Commands: ppse, PPSE, and Baaa . . . . . . . . . . . . . . . . . 16

6 Examples for ppse, PPSE, and Baaa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

7 Error Code Explanations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

List of Figures

1 MX2A Dimensional Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 MX2A Electrical Connection Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 Graph of MX2A Gas Dependence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Graph of Analog Output Functions Available on the MX2A . . . . . . . . . . . . . . . . . . . . . 13

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Instruction Manual MX2A Active Thermocouple Gauge

1 Introduction

1.1 Disclaimer

All information in this manual is subject to change without notice. The Fredericks Company assumes
no responsibility for inaccuracies in product specifications or any liability arising from product use.
Please contact Televac at [e-mail] or call 215-947-2500 with comments or questions.

1.2 Description

The MX2A is a thermocouple vacuum gauge with a range of 1 × 10−4Torr to 1000 Torr. It utilizes a
Televac thermocouple vacuum sensor, part number 2-2126-0YY. It has a two color OLED display with
selectable units of Torr, Millibar, and Kilopascal. Settings can be changed through RS-485 communi­cations with a PC or on the unit using four capacitive touch buttons located on the top of the unit. The
MX2A has 2 set points, one relay and one open collector, and a selectable analog output option. The
analog output has a variety of options including four linear outputs, linear by decade, logarithmic,
and non-linear.

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Instruction Manual MX2A Active Thermocouple Gauge

1.3 Operating Specifications

Table 1: Operating Specifications

Operating Range 1 × 10−4to 1000 Torr
Communications RS-485
Programmable Set Points 2
Set Point 1 Open Collector
Set Point 2 Relay
Analog Output 7 selectable 0 to 10 V
Supply Voltage +22 to +26 V DC
Maximum Power 8 W
Supply Voltage +22 to +26 V DC
Calibration Medium Dry air or nitrogen
Overpressure 150 PSI
Digital Output Resolution 2 significant digits with exponent
Analog Output Resolution 16 bits
Operating Temperature 0◦C to 50◦C
Storage Temperature −20◦C to 60◦C
Bakeout Temperature

Brass (P/N: 2-8910-110)

Stainless (P/N: All Others)
Response Time ≤ 2 second
Accuracy

1 mTorr to 10 mTorr

10 mTorr to 10 Torr

10 Torr to 100 Torr

100 Torr to 1000 Torr

Analog Output

Standard Resolution

1 mTorr to 500 mTorr

500 mTorr to 5 Torr

5 Torr to 50 Torr

50 Torr to 500 Torr

500 Torr to 1000 Torr

Display Readable Distance 3 m (10 feet)

100◦C (electronics removed)
200◦C (electronics removed)

±1 mTorr
±10%
±30%
±10%
±5 mV

1 mTorr
10 mTorr
100 mTorr
1 Torr
10 Torr

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Instruction Manual MX2A Active Thermocouple Gauge

1.4 Dimensions

Figure 1: MX2A Dimensional Drawing

1.5 Safety Information

START BY READING THESE IMPORTANT

SAFETY INSTRUCTIONS AND NOTES

In these instructions the word “product” refers to the MX2A and all of its approved parts and acces­sories. NOTE: These instructions do not and cannot provide for every contingency that may arise in
connection with the installation, operation, or maintenance of this product. Should you require further
assistance, please contact Televac at the email address on the second page of this manual.

This product has been designed and tested to offer reasonably safe service provided it is installed,
operated, and serviced in strict accordance with these safety instructions.

These safety precautions must be observed during all phases of operation, installation, and service
of this product. Failure to comply with these precautions or with specific warnings elsewhere in this
manual violates safety standards of design, manufacture, and intended use of the instrument. Televac
disclaims all liability for the customer’s failure to comply with these requirements.



READ Instructions – Read all safety and operating instructions before operating the product.



RETAIN instructions – Retain the safety and operating instructions for future reference.



HEED warnings – Adhere to all warnings on the product and in the operating instructions.



FOLLOW instructions – Follow all operating and maintenance instructions.

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Instruction Manual MX2A Active Thermocouple Gauge



ACCESSORIES – Do not use accessories not recommended in this manual as they may require a
technician to restore the product to its normal operation.

The MX2A qualifies as a Safety Extra-Low Voltage (SELV) device. As such, it represents little to no
hazard concerning electrical shock or burns.

Do not substitute parts or modify instrument. Because of the danger of introducing addi­tional hazards, do not install substitute parts or perform any unauthorized modifications
to the product. Return the product to Televac for service and repair to ensure that safety
features are maintained. Do not use this product if it has unauthorized modifications.

The MX2A is not designed to be serviced by the operator. Any service should be done by a Tele­vac technician. However, in the event of any attempt to service the unit, please remove the power
supply to minimize the risk of harm.

The 2A sensor is user-replaceable and additional 2A sensors can be ordered from Televac by the
operator. Do not attempt to use other sensors with the MX2A remote. Using another sensor may
result in damage to the MX2A and voids any warranty in place.

2 Setup

2.1 Installation

Each MX2A is designed to be used in conjunction with a 2A sensor. The 2A sensor can be mounted in
any orientation for accurate measurement up to 10 Torr. For measurements up to atmosphere, mount
the 2A sensor in an upright position. The sensor should be mounted close to the area where vacuum
measurement is desired. Failure to mount the 2A in a vertical position will decrease the accuracy of
the measurement between 10 Torr and atmosphere, but will leave the accuracy below 10 Torr unaf­fected. Each 2A sensor has a key that only allows the MX2A to mate with the sensor in the proper
orientation. Rotate the MX2A until the correct alignment is obtained and the MX2A is able to slide
onto the 2A sensor. Connect the power connector to the top of the unit and be sure to tighten the
screws so that a firm connection is maintained.

Try to avoid connecting the MX2A to the vacuum chamber by long or narrow piping as this may
affect the accuracy and response time of the unit. Avoid mounting the unit near a heater within the
chamber as this may affect the measurement accuracy. Excessive vibration of the unit may affect
accuracy and decrease the life of the unit. Exposure to oils and other contaminants will decrease the
accuracy and decrease the life of the sensor. Do not expose the unit to corrosive gases.

2.2 Electrical Information

Power connectors and adaptors for use with the MX2A are available for purchase from Televac. Op­erators wishing to create their own adaptors should refer to the pin out of the MX2A below. Each
connection labeled “Floating” has no connection and should remain so.

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