Laurel Electronics LTS6 User Manual

Model LTS6

RS232 OR RS485 SERIAL INPUT,

ANALOG OUTPUT TRANSMITTER

Modbus or Custom ASCII Protocol

OWNERS MANUAL

LAUREL Electronics Inc.

3183-G Airway Ave, Costa Mesa, CA, 92626, USA
Tel: [phone] Fax: [phone] • Website: www.laurels.com

1. ORDERING GUIDE, SERIAL INPUT TRANSMITTER

48 Vdc

Configure a model number in this format: LTS600, CBL04

LTS6…Transmitter with 4-20 mA, 0-20 mA

or 0-10V isolated analog output,
RS232 or RS485 serial data input, and
dual 120 mA solid state relays. Default
jumpered for RS232.

LTSE6E… Transmitter with 4-20 mA, 0-20

mA or 0-10V isolated analog output,
Ethernet serial data input, and dual 120
mA solid state relays.

Power

0.............................85-264 Vac or 90-300 Vdc

1.................................12-30 Vac or 10-

2. TABLE OF CONTENTS

ACCESSORIES

CBL04……RS232 cable, two 3-pin connec-

tors on transmitter end, DB9 con­nector on computer end.

CBL02……USB to DB9 adapter cable. Can be

used with CBL01 or CBL04.

1. ORDERING GUIDE, SERIAL INPUT TRANSMITTER .......................................................... 2

2. TABLE OF CONTENTS ....................................................................................................... 2

3. INTRODUCTION, SERIAL INPUT TRANSMITTER.............................................................. 3

4. RECEIVING & UNPACKING YOUR TRANSMITTER ........................................................... 3

5. SAFETY CONSIDERATIONS .............................................................................................. 4

6. TRANSMITTER FIELD WIRING ......................................................................................... 5

7. PROGRAMMING YOUR TRANSMITTER............................................................................ 6

8. CHANGING JUMPER SETTINGS ....................................................................................... 8

9. DUAL RELAY OPERATION ............................................................................................... 10

10. MODBUS PROTOCOL TRANSMITTER COMMUNICATIONS .............................................. 12

11. CUSTOM ASCII PROTOCOL TRANSMITTER COMMUNICATIONS .................................... 17

12. SPECIFICATIONS, SERIAL INPUT TRANSMITTER ............................................................ 20

13. WARRANTY ...................................................................................................................... 24

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3. INTRODUCTION, RS232 OR RS485 SERIAL INPUT TRANSMITTER

The LTS6 serial input to analog output transmitter (or serial-to-analog converter) accepts RS232
or RS485 serial data using the Modbus or Custom ASCII protocol, and converts it to an isolated,
scalable 4-20 mA, 0-20 mA or 0-10V analog output. The unit fits on a 35 mm DIN rail and is only

22.5 mm (0.89") thick. It is normally powered by AC (85-264 Vac), but can optionally be powered
by low voltage AC or DC. All electrical connections are via detachable screw-clamp plugs. A
separate manual covers the LTSE6 serial input to analog output transmitter, which accepts
Ethernet data and converts to an isolated, scalable 4-20 mA, 0-20 mA or 0-10V analog output.

The current or voltage transmitter output is jumper selectable and is transformer isolated to avoid
ground loops. Either output provides 16-bit resolution of the output span and is ultra-linear to
within one bit. The output is scaled to the serial input in software. Output accuracy is ±0.02% of
span.

Dual solid state relays rated 120 mA at 140 Vac or 180 Vdc are standard. The relays can respond
to the transmitted serial values or to transmitted control characters, which override the internal
setpoints. The relays can also be controlled independently of the serial input by applying signals to
control inputs 1 and 2.

Isolation to 250V rms is provided for power, the serial data input, analog output, and relay
outputs. Isolation adds safety and avoids possible ground loops.

Default serial settings are for RS232 and full-duplex RS485. Half-duplex RS485 can be selected
via jumpers or external wiring.

Transmitter setup is via the unit’s serial port using an external PC and Instrument Setup software.
This software can be downloaded from our website at no charge. The required 3-wire transmitter­to-PC interface RS232 cable is easy to build and is also available for purchase.

4. RECEIVING & UNPACKING YOUR TRANSMITTER

Your transmitter was carefully tested and inspected prior to shipment. Should the transmitter be
damaged in shipment, notify the freight carrier immediately. In the event the transmitter is not
configured as ordered or is inoperable, return it to the place of purchase for repair or replacement.
Please include a detailed description of the problem.

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5. SAFETY CONSIDERATIONS

Warning: Use of this transmitter in a manner other than specified may impair the protection of

the device and subject the user to a hazard. Visually inspect the unit for signs of damage. If the unit is
damaged, do not attempt to operate.

Caution:

• This unit may be powered with AC (mains) from 85-264 Vac or 90-300 Vdc with the high voltage
power supply option, or 12-30 Vac or 10-48 Vdc with the low voltage power supply option. Verify
that the proper power option is installed for the power to be used. This transmitter has no AC
(mains) switch. It will be in operation as soon as power is applied.

• The 85-264 Vac or 90-300 Vdc mains connector (P1 Pins 1-3) is colored green to differentiate it
from other input and output connectors. The 12-30 Vac or 10-48 Vdc mains connector is colored
black.

• To avoid dangers of electrocution and/or short circuit, do not attempt to open the case while the
unit is under power. However, signal wiring changes external to the case can be made safely while
the unit is under power.

• To prevent electrical or fire hazard, do not expose the transmitter to excessive moisture.

• Do not operate the transmitter in the presence of flammable gases or fumes. Such an environment

constitutes an explosion hazard.

• Secure the transmitter to a 35 mm DIN rail.

Symbols used:

Caution (refer to accompanying
documents)

PROVISION FOR COOLING

Caution, risk of electric shock.
Equipment protected throughout

by double insulation or reinforced

AL 1

AL 2

AL 1

AL 2

AL 1

AL 2

AL 1

AL 2

AL 1

AL 2

insulation.

RESET

RESET

RESET

Earth (ground) terminal.

Both direct and alternating current.

Operating environment:

• Class II (double insulated) equipment
designed for use in Pollution degree 2.

RESET

POWER

POWER

POWER

POWER

To avoid overheating, mount transmitters
with ventilation holes at topand bottom.
Leave a minimum of 6 mm (1/4”)between
transmitters, or force air with a fan.

RESET

POWER

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6. TRANSMITTER FIELD WIRING

Control input 2

Control input 1

GND

Analog out - 1

Analog out + 2

AL2 1

AL2 2
AL1 3
AL1 4

6 TX
5 RX
4 NC
3 GND
2 BRX
1 N/C

Transmitter

1
2
3

P5 Control

inputs 1 & 2

RS485

6 N/C
5 ARX
4 ATX

P4 Analog

output

P2 Serial

data I/O

3 GND
2 BRX
1 BTX

P3 Solid

state relays

P1 Power

input

3 Power GND
2 AC neutral or -DC

RS232

TX
RX
NC
GND
GND
N/C

1 AC high or +DC

5
4
3
2
1

DB9 connector

9
8
7
6

6 N/C
5 ARX
4 ATX
3 GND
2 BRX
1 BTX

ATX
ARX
GND
BTX
BRX

to PC

(rear view)

Transmitter Master

RS232 wiring

6 N/C
5 ARX / ATX
4 N/C
3 GND
2 BRX / BTX
1 N/C

Transmitter

RS485 wiring, half duplex

with internal jumpers.

ATX / ARX

GND
BTX / BRX

Master

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Transmitter Master

RS485 wiring, full duplex-

6 N/C
5 ARX

ATX / ARX

4 ATX
3 GND
2 BRX

GND
BTX / BRX

1 BTX

RS485 wiring, half duplex

with external jumpers.

7. PROGRAMMING YOUR TRANSMITTER

OVERVIEW

Serial input transmitters are programmed using a PC with an RS232 port and Instrument Setup
(IS) software, which provides a graphical user interface. The software allows uploading, editing,
downloading and saving of setup data.

CONNECTING TO YOUR PC

Use a 3-wire RS232 cable (P/N CBL04) to connect your transmitter to the COM port of your PC.
Download the file
Instrument Setup Software” and follow the prompts. To launch IS software, press on

Programs => IS2 => Instrument Setup

a brief splash screen, the

ESTABLISHING COMMUNICATIONS

ISx_x_x.exe

Communications Setup

from our website and double-click on the file name. Click on “Install

Start =>

or on the desktop icon that you may have created. Following

screen will appear.

In the
default setting. Select

(USB)

Communications Setup

Transmitter LTA, LTM, LTS

button. In the resulting

screen, select

Custom ASCII

as the Device Type. Then click on the

Establish Communications

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as the Protocol, as this is the factory

RS-232

screen, select your Com Port and

9600

as the Baud Rate. You will be able to change your protocol and baud rate later under the

Communication

turn green and display your communication parameters and the counter-transmitter revision level.
Click on
that you run IS software.

Main Menu

setup tab. Click on

. The computer will remember your communication settings for the next time

Establish

, and the two fields at the bottom of the screen should

The best way to learn IS software is to experiment with it. From the
=>

Get Setup

View

=>
menus and other selection tools. You can download (or put) your edited file into the transmitter by
clicking on

and retrieve a previously saved file from disk by click on

Setup

After selecting a screen input field, pressing the F1 key will bring up detailed help information for
that field.

to retrieve (or get) the existing setup data from your counter-transmitter. Click on

Setup

to bring up screens which allow you to easily edit the setup file using pull-down

Counter

=>

Put Setup

. You can save your setup file to disk by clicking on

File

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Main Menu

=>

Open

.

, click on

File

Counter

=>

Save

SETTING UP BASIC OPERATION

Under the

Filter

, and

Under
Remote S and Remote C operating modes, which are explained under the “Custom ASCII Protocol
Transmitter Communications” section of this manual.

The

Control Inputs

2, or both. Selections applicable to the serial input transmitter are the following:

•

Meter Reset, Function Reset, Meter Reset

Control Input 2 (causes a function reset, which resets latched alarms.

•

Activate Alarm 1, Activate Alarm 2, Activate Alarm 1&2

Control Input 1 activates relay 1, grounding Control Input 2 activates relay 2, and grounding
both inputs activates Alarms 1 & 2.

•

Tare Enable, Tare if Enabled, Tare

1 (normally with a permanent connection) enables the Tare function. Momentarily grounding
Control Input 2 stores the current digital value as an offset and subtracts this offset from the
digital reading sent to the transmitter, resulting in a zero value for alarms and the analog output.
This offset will also be subtracted from all new readings sent to the transmitter. To change the
offset, momentarily ground Control Input 2 for the new input.

Input+Display

Power-On Total

Display

, select

tab, select 000.00 Secs for

, as these parameters do not apply to the serial input transmitter.

Remote A, Remote S

pull-down menu controls the effect of grounding Control Input 1, Control Input

(last row). When this row is selected, grounding Control Input

or

Remote C

(first row). When this row is selected, grounding

Time Out

. These items correspond to the Remote A,

. Ignore

. When this row is selected, grounding

Signal Input, Gate Time

,

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