Detcon Remote Sensor User Manual

Model 700

Remote Sensor/Alarm Relay Module

Operator’s Installation and Instruction Manual

The Woodlands, Texas 77387

Ph.281.367.4100 / Fax [phone]

March 16, 2011• Document #3220• Revision 1.0

DETCON, Inc.

3200 Research Forest Dr.,

www.detcon.com

700 RAM I.M.

This page left intentionally blank

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: 281.292.286 0 •

700 RAM I.M. ii

www.detcon.com • [e-mail]

700 RAM I.M.

Table of Contents

1. Introduction ..................................................................................................................................................1

1.1 Description.......................................................................................................................................... 1

1.2 Installation .......................................................................................................................................... 1

1.3 Field Wiring........................................................................................................................................ 3

2. Operator Interface.........................................................................................................................................5

3. Set-up and Normal Operation.......................................................................................................................7

3.1 View Sensor Status............................................................................................................................. 7

3.2 Set AutoSpan Level ............................................................................................................................ 8

3.3 Set Serial ID........................................................................................................................................ 8

3.4 Set-up for Relay Outputs .................................................................................................................... 8

3.5 Signal Output Check......................................................................................................................... 10

4. RS-485 Modbus™ Protocol.........................................................................................................................10

5. RAM Electronics Warranty........................................................................................................................11

6. Specifications .............................................................................................................................................11

6.1 Spare Parts ........................................................................................................................................ 12

6.2 Revision Log..................................................................................................................................... 13

Table of Figures

Figure 1 700 RAM ............................................................................................................................................... 1

Figure 2 RAM Mounting...................................................................................................................................... 2

Figure 3 Mounting RAM with 700 Sensor........................................................................................................... 2

Figure 4 Exploded View of Assembly................................................................................................................. 3

Figure 5 Interface connections on terminal board................................................................................................ 3

Figure 6 Installation with 700 Gas Sensor ........................................................................................................... 4

Figure 7 Remote 700 Gas Sensor with RAM....................................................................................................... 4

Figure 8 RAM Software Flowchart...................................................................................................................... 6

Phone: [phone] • Fax: 281.292.286 0 •

700 RAM I.M. iii

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

www.detcon.com

• [e-mail]

700 RAM I.M.

This page left intentionally blank

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: 281.292.286 0 •

700 RAM I.M. iv

www.detcon.com • [e-mail]

700 RAM I.M.

1. Introduction

1.1 Description

The Model 700 Remote Sensor/Alarm Relay Module (known as the Remote Alarm Module or RAM) is sold
separately as an accessory for Model 700 Gas Sensors. It is a universal design and can be used with any of
the Model 700 Gas Sensors. The RAM is provided in an explosion-proof junction box constructed of either
epoxy-painted aluminum (

Figure 1) or 316 stainless steel and includes a glass-viewing window.

Figure 1 700 RAM

The RAM performs two main functions. The first function is to set gas alarm levels and to configure the
three local relay contacts. The second function is to operate a Model 700 Gas Sensor remotely. The remote
sensor function is typically used when the sensor must be mounted in a position where it cannot be viewed or
accessed readily. Both functions can be used at the same time.

The RAM provides the 4-20mA output directly from the Model 700 Gas Sensor. The RAM acts as a
Modbus™ master to the Model 700 Gas Sensor in order to display the reading and execute the remote
control functions. It acts as a Modbus™ slave to any master control device and simply repeats the
Modbus™ output from the 700 Gas Sensor it is connected to.

1.2 Installation

The RAM can be installed as a wall mount or pipe mount using the mounting holes of the explosion-proof
junction box. It should be oriented such that the LED display is horizontal. If the 700 Gas Sensor is
mounted directly to the RAM, use 0.5” spacers underneath the mounting holes to provide access clearance
for the 700 Gas Sensor (

NOTE: Block any unused ¾” NPT holes with the proper Plug. (Detcon P/N 8522-750)

Figure 3).

700 RAM I.M. Rev. 1.0 Page 1 of 13

700 RAM I.M.

5.825"

5.2"

5.5"

Three - ¾" NPT Fittings

Ø0.2750 x2

Mounting Holes

Explosion Proof Enclosure

Junction-Box

4.35"

Bolt

Mounting

Wall (or other

mounting surface)

Figure 2 RAM Mounting

5.5"

5.2"

¾" NPT x3

4.35"

5.825"

Ø0.275 x2

Mounting Holes

Spacer

Bolt

Mounting

Explosion Proof Enclosure

Junction-Box

(Aluminun Junction-Box shown)

12.945"

7.76"

5.195"

Use Spacers to mov e

the J-Box and Sensor

detcon inc.

MODEL

XX-700

Sensor

2.115"

PGM2

SPAN

PGM1

ZERO

Assembly away from the

wall at least 0.25-0.5" to

allow access to Sensor

Sensor Assembly

PGM2

SPAN

Wall (or other

mounting surface)

Splash Guard

2"

Figure 3 Mounting RAM with 700 Sensor

The RAM Electronics package consists of three printed circuit assemblies (PCAs). The top two PCAs (RAM
display and RAM connector board) and the RAM faceplate are enclosed in a molded plastic retaining guard
and can be accessed by removing the junction box cover and using the brass pull knobs to pull the package
directly out of the enclosure. The bottom PCA (terminal board) will remain attached to the bottom of the

700 RAM I.M. Rev. 1.0 Page 2 of 13