TELEVAC MX4A Instruction Manual

The Fredericks Company

MX4A Active Convection Gauge

Instruction Manual

The Fredericks Company - Televac

2400 Philmont Avenue

Huntingdon Valley, PA 19006

web: www.frederickscompany.com

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tel: [phone]

fax: [phone]

Instruction Manual MX4A Active Convection Gauge

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

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

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

2.5.2 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

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

2.5.4 Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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

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

3 RS-485 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.1 Changing Communications Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

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

3.3 RS-485 Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.4 RS-485 Sample Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.5 RS-485 Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

List of Tables

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

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

3 RS-485 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4 RS-485 Command Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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

6 Examples for ppse, PPSE, and Baaa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7 Error Code Explanations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

List of Figures

1 MX4A Dimensional Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 MX4A Electrical Connection Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Graph of MX4A Gas Dependence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Graph of Analog Output Functions Available on the MX4A . . . . . . . . . . . . . . . . . . . . . 13

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Instruction Manual MX4A Active Convection 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 MX4A is a convection vacuum gauge with a range of 1× 10−4Torr to 1000 Torr. It utilizes a Televac
convection vacuum sensor, part number 2-2120-0YY. 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 MX4A 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 MX4A Active Convection 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
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: 2-8930-110)

Stainless (P/N: All Others)
Response Time ≤ 1 second
Accuracy

1 mTorr to 10 mTorr

10 mTorr 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%
±5 mV

1 mTorr
10 mTorr
100 mTorr
1 Torr
10 Torr

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Instruction Manual MX4A Active Convection Gauge

1.4 Dimensions

Figure 1: MX4A Dimensional Drawing

1.5 Safety Information

START BY READING THESE IMPORTANT

SAFETY INSTRUCTIONS AND NOTES

In these instructions the word “product” refers to the MX4A 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 found in the footer of this manual.

This product has been designed and tested to offer reasonably safe service provided in 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.



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

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Instruction Manual MX4A Active Convection Gauge

The MX4A 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 onj 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.

2 Setup

2.1 Installation

Each MX4A is designed to be used in conjunction with a 4A sensor. Mount the 4A sensor in an upright
position and as close to the area where vacuum measurement is desired. Failure to mount the 4A
sensor in a vertical position will decrease the accuracy of the measurement above 10 Torr. Each 4A
sensor has a key that only allows for the MX4A to mate with the sensor in the proper orientation.
Rotate the MX4A until the correct alignment is obtained and the MX4A is able to slide onto the 4A
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 MX4A 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 MX4A are available for purchase from Televac. Op­erators wishing to create their own adaptors should refer to the pin out of the MX4A below. Each
connection labeled “Floating” has no connection and should remain so.

Figure 2: MX4A Electrical Connection Information

Pin Description
1 Analog Output (Ground)
2 RS-485 (-)
3 SP2 NC
4 SP2 NO
5 SP1 Open Drain
6 Floating
7 Floating
8 Supply Voltage
9 Analog Output (0 to 10 V)
10 RS-485 (+)
11 SP2 Com
12 SP1 Source
13 Floating
14 Floating
15 Ground

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