Rice Lake EL232 XPCD User manual

16942
EL232 XPCD
Explosion Proof Remote Display
Installation Manual
To be the best by every measure

1
Contents
About This Manual................................................................................................................................... 1
1.0 Introduction.................................................................................................................................. 5
1.1 System Limitations and Restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Front Panel Annunciators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.0 Installation and Wiring................................................................................................................ 7
2.1 EL232 XPCD Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.1 Mounting and Mounting Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Sealoff Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Cabling and Conduit Runs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.1 Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2 Conduit Runs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4 AC Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.0 Indicator Setup........................................................................................................................... 12
3.1 Serial Data Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.1 Condec Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.2 Electroscale Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.3 Analogic Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1.4 Cardinal Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2 Serial Data Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.1 RS232 C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.2 20 mA Active Current Loop Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2.3 20 mA Passive Current Loop Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3 Configuration of the EL232 XPCD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3.1 Loss of Signal Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.4 Serial Data Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.0 EL232 XPCD Operation............................................................................................................... 19
4.1 Lamp Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2 Software Revision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3 Current Baud Rate Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.4 Input Signal Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.5 Indicator Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.6 Receiving Data for the First Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.0 Appendix.................................................................................................................................... 21
5.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.2 Recommended Spare Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.3 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
EL232 XPCD Limited Warranty............................................................................................................... 23
Copyright © 2002 Rice Lake Weighing Systems. All rights reserved. Printed in the United States of America.
Specifications subject to change without notice.
March 2002

2 ES232 XPCD Installation Manual

1
About This Manual
The EL232 XPCD explosion proof remote display represents the latest in state-of-the-art microprocessor
technology specifically applied to the explosion proof weighing marketplace. This EL232 has been modified for
use in a hazardous electrical environment.
This manual provides information on installation of the EL232 XPCD. The installer should be familiar with the
National Electrical Code and RP 12.6 ( Recommended Practice ) requirements for installation of equipment in
hazardous areas (NEC Article 504, Intrinsically Safe Systems ) published through the Instrument Society of
America.
This equipment is intended only for industrial applications.
This instrument and accompanying equipment must be installed and serviced by an
authorized technician in accordance with the instructions provided in this manual.
Improper specification, installation, or service of this equipment could result in personal injury or property
damage.
Read all of the manual prior to installation. Do not assume that all hazardous area installations are identical.
Do not begin installation until all safety procedures are in place including lockouts, additional ventilation, or
washdowns. Make sure plant safety personnel have checked the area in which you will be working and have
officially declared it safe for work to proceed.
All explosion proof enclosures must remain closed unless being serviced by qualified personnel in an area
which safety inspectors have tested and declared safe. All other openings have sealoff fittings or plugs
provided. Each opening must have a sealoff fitting or plug correctly installed in it. Sealoff installation is
critical. Maximum voltage inside of enclosure must not exceed 250VAC.
The illustrations shown on the following pages represent a basic explosion proof flame control theory
(XPCD).
Warning

2 EL232 XPCD Installation Manual
The push buttons, rotary switches and sealing fittings are all attached to the enclosure via drilled and
tapped holes in the enclosure. Just as with the flange, all threaded operators and fittings carefully control
the flame path.
Explosion
HAZARDOUS
AREA
High temperature
gases
Cooling from
conduction of heat
along the threads
There must be a minimum of five full
threads of engagement of a 2–A
2–B fit for a Group C enclosure.
Group B increases this to eight full
threads of engagement.
Propagation of gas due to
pressure from an internal
explosion is along the
threads
Shaft clearance
not to exceed 0.00033”
Cross–section of a
shaft-type threaded
operator
INSIDE OF
ENCLOSURE
Lower
temperature
gases
Enlarged view
below

3
The design intent of an explosion proof enclosure is not to contain an explosion, but to control it. The flame
path is carefully controlled at the flanges. This insures that if an explosion occurs, any gases that escape will
be cooled to a temperature below the ignition point of any atmosphere specified within that enclosure’s
rating.
Explosion
HAZARDOUS
AREA
High temperature
gases
Cooling from
expansion of gas
(Boyle’s Gas Law)
The distance from the boundary of
the inside of the enclosure to the
gasket is known as the Flame Path.
This distance must be at least 1" for
Group C throughG.
INSIDE OF
ENCLOSURE
Lower
temperature
gases
Enlarged view
below
Propagation of gas due to
pressure from an internal
explosion
Gasket
For clarity, the slope of the flange
faces has been greatly enhanced
(Typically, the slope is .0015"/inch)

4 EL232 XPCD Installation Manual

Introduction 5
1.0 Introduction
The EL232 XPCD is a high performance serial remote data display. It receives serialASCII data (20 mA current
loop or RS-232), and displays weight data on a 8" LED display. Five LED status indicators are provided for Lbs,
Kg, Gross, Net, and no signal. (see Figure 1-1 on page 6).
The EL232 XPCD supports twelve scale formats which include:
• UMC Series
• General Freedom I and II
• Electroscale 560
•A& D Instruments 4322, 4323, 4316
•Weightronix WI-110 and WI-120
•Toledo indicators with “High speed data format”
• Flex-weigh DWM-4
•Analogic AN5315, AN5316, AN5322
• Masstron M-2500 and M-5000
•Fairbanks 90-164 series
• Streeter Richardson 9000
• Cardinal 738
• Instruments with programmable ASCII output
• Generic smart receiver mode
1.1 System Limitations and Restrictions
The following items represent limitations and restrictions on the use of the EL232 XPCD:
• All wiring, connections, conduit and grounds must comply with the National Electrical Code.
• No modifications can be made in the field.
• It is mandatory to return the EL232 XPCD to Rice Lake Weighing Systems for service.

6 EL232 XPCD Installation Manual
1.2 Front Panel Annunciators
Figure 1-1 illustrates the EL232 XPCD front panel which include six LED display digits and five LED
annunciators.
Figure 1-1. EL232 XPCD Front Panel
CLASS I
DIVISION 2
GROUP C & D
CLASS II
DIVISION 1
GROUP E F & G
TO PREVENT IGNITION OF
HAZ. ATMOS., DISCONNECT
ORE OPENING. KEEP
CIRCUIT IS ALIVE
FROM SUPPLY BEF
ASS'Y TIGHT WHILE
CAUTION:
REMOTE WEIGHT DISPLAY
LBS KGS GROSS NET NO SIGNAL
MADE IN U.S.A.

Installation and Wiring 7
2.0 Installation and Wiring
This section is provided to help the installer and describes the procedures for installing the EL232 XPCD remote
display and enclosure, AC wiring, conduit runs, and internal modifications for the EL232 XPCD.
2.1 EL232 XPCD Enclosure
The following sections describe mounting locations and how to mount the enclosure and sealoff the fittings.
2.1.1 Mounting and Mounting Locations
The mounting and installation of an explosion proof enclosure is more involved than a general purpose unit and it
is recommended that all outdoor installations have a shelter, roof, enclosure, or covering. The EL232 XPCD
enclosure is cast aluminum and direct sunlight can cause it to heat to a very high temperature which can damage
the electronics inside. (Such damage is not covered by the warranty). Sheltering the unit from sunlight will help
control the internal temperature. In cold climates, it is recommended an indicator heater be installed (optional).
These are small and easily installed on the backplate.
Sunlight and variable temperatures can also cause moisture to condensate inside the enclosure. It is
recommended to shelter the outdoor installation by a shelter, roof, enclosure, or covering. Moist environments
can also be controlled by the use of desiccants. Contact your local dealer for information on desiccants.
Do not place desiccants on top of circuit boards. Place them in the bottom of the
enclosure away from electronics and wires.
The explosion proof enclosure is substantially heavier than a standard enclosure and thus the mounting surface
must be capable of reliably supporting the added weight.
The mounting and installation of the EL232 XPCD must be into Division II or safe electrical area per NEC,
Section 500. The inside of an explosion proof enclosure is classified as a Division II environment.
Glass Face
The glass face on the EL232 XPCD may look indestructible but it is not. If damaged in any way, the entire unit
must be completely turned off at the source until it is replaced. The enclosure must be protected from blows and
scrapes from passing equipment, falling objects, thick glues or resins, certain acids which eat aluminum, and
other hazards which can break or damage the enclosure.
The glass window in the enclosure must be not become scratched, pitted, or damaged in any way. Do not wipe
the glass with dirty gloves or rags as this can cause the glass to become scratched.
!Caution

8 EL232 XCPD Installation Manual
2.2 Sealoff Fittings
The utmost care must be taken to completely seal the inside of the remote display off from the outside world. To
do this all wiring into and out of the enclosure must be in conduit using sealoff fittings between the remote
display and the conduit. The sealoff fittings ensure that the hazardous atmosphere does not travel either through
the conduit or through insulation or wiring back to the safe area. The graphic shown below illustrates the location
of sealoff fittings.
These fittings, once installed and sealed are very difficult to remove so make sure all the wiring has been double
checked before beginning. If rigid conduit is not being used for connection to the scale base, be sure to install an
approved strain relief fitting to avoid pulling the wires out of the sealoff fittings in an accident. Doing so would
open a flame path to the enclosure and defeat its purpose.
Note: The inside of an explosion proof enclosure is considered a Division II area when the enclosure has
been properly sealed.
SEAL FITTING
18" MAX.
FROM BOX
MAKE SURE THE MOUNTING SUPPORT IS CAPABLE
OF HOLDING CONDUIT TIGHT AGAINST IT. NO
STRAIN MUST BE PLACED ON THE SEALOFF
FITTING ASSEMBLY.
WHEN USING FLEXIBLE CONDUIT, USE
MULTIPLE PIPE STRAPS TO SECURE
RIGID CONDUIT TO THE SUPPORT
STRUCTURE. ATTACH THE FLEXIBLE
CONDUIT TO THE RIGID CONDUIT ONLY
AFTER MULTIPLE STRAPS HAVE BEEN
ATTACHED TO PREVENT ANY STRAIN
FROM REACHING THE SEAL-OFF FITTINGS.
CLASS I
DIVISION 2
GROUP C & D
CLASS II
DIVISION 1
GROUP E F & G
TO PREVENT IGNITION OF
HAZ. ATMOS., DISCONNECT
ORE OPENING. KEEP
CIRCUIT IS ALIVE
FROM SUPPLY BEF
ASS'Y TIGHT WHILE
CAUTION:
REMOTE WEIGHT DISPLAY
LBS KGS GROSS NET NO SIGNAL
MADE IN U.S.A.

Installation and Wiring 9
2.3 Cabling and Conduit Runs
2.3.1 Cabling
There are two types of cables that pass through a sealoff fitting, single conductor and multi conductor.
Single Conductor Cabling
Single conductor cables are typically redundant ground wires (used with resistive intrinsic safety barrier). Due to
the nature of the method by which insulation is applied to wire, a single conductor wire (single or multi strand)
can be considered gas tight. It is not necessary to strip the insulation back ahead of entry into the safe area. Single
conductor cables will pass through a sealoff fitting as shown below.
Figure 2-1. Single Conductor Cable
Multi Conductor Cabling
Multi conductor cables may be load cell cables, AC power, serial data inputs or other signals. Because of the
airspace that typically exists within the outer insulation of a multi conductor cable, they cannot be considered gas
tight. Therefore, to insure that the explosion proof enclosure is allowed to vent internal pressure appropriately,
the outer insulation must be removed back to the point ahead of entry into the safe area. Multi conductor cables
will pass through a sealoff fitting as shown below.
Figure 2-2. Multi Conductor Cable
A sealing fitting must be installed within 18" of the enclosure for Groups C-G and 6" for Groups A and B.
Using the enclosed packing fiber and sealing cement, follow the directions for sealing the sealoff fittings
carefully. Make sure there are no openings, no matter how small to the outside.
An enclosure without sealoff fittings correctly installed and sealed is not explosion proof
therefore can pose serious injury or death.
Conduit to Indicator or other Safe
Area ( 18" Max. Group C & D)
Packing Plug
Safe Area
Airspace
Hazardous Area
Airspace
Conduit or Strain Relief
to Hazardous Area
Packing Fiber
Sealing Cement
Single
Conductor
Cable
Conduit to Indicator or other Safe
Area ( 18" Max. Group C & D)
Packing Plug
Safe Area
Airspace
Hazardous Area
Airspace
Conduit or Strain Relief
to Hazardous Area
Packing Fiber
Sealing Cement
Multi-Conductor
Cable
Warning

10 EL232 XCPD Installation Manual
2.3.2 Conduit Runs
Conduit can be run either vertically or horizontally. But either way the conduit must be sealed properly to
maintain the explosion proof integrity of the unit. The following paragraphs explain the proper way to install a
conduit run and the sealing fittings.
Horizontal Conduit Runs
Install the fitting with covered filling opening facing up. Remove the threaded cover and pack Adaco
®
packing
fiber around and between cables at both ends of fitting to block the flow of cement into conduits. Packing fiber
must not project into the main cavity of fitting. The cavity length free of packing fiber must be at least equal to
inside diameter of conduit but not less than 5/8".
Mix the cement per label instructions using the enclosed shipping container. Fill the container with clean cold
water to “water line” (make sure not to exceed required amount of water). Gradually pour cement from the
plastic bag into water and stir thoroughly for proper mixture. Fill the fitting in one continuous pour to the top of
filling opening within five minutes after mixing cement. Tamp with a blunt stick to expel any air bubbles. Install
and tighten filling opening cover.
Fittings requiring more than 16 oz. of cement must be filled from a single mixture of cement and water. Do not
pour in stages.
Water-mix sealing compound should not be poured or installed at temperatures below 35° F. Adaco
no. 1 sealing cement must be used as a part of Adalet UL listed fittings.
Vertical Conduit Runs
Install the fitting with angled fill plug or cap fill plug towards the top. Remove angled fill plug, large hole plug or
threaded cover. Pack Adaco packing fiber around and between cables at lower end of sealing fitting to block flow
of cement into conduit. Packing fiber must not project into main cavity of fitting. Install and tighten large plug or
threaded cover with fill plug facing up but do not install fill plugs at this time.
Mix the cement per label instructions using the enclosed shipping container. Fill the container with clean cold
water to “water line” (make sure not to exceed required amount of water). Gradually pour cement from the
plastic bag into water and stir thoroughly for proper mixture. Fill the fitting in one continuous pour to the top of
filling opening within five minutes after mixing cement. Tamp with a blunt stick to expel any air bubbles. Install
and tighten fill plug.
!Caution

Installation and Wiring 11
2.4 AC Power Wiring
Electrical connections made in an explosion proof
installation are made through rigid steel conduit
through threaded openings in the back or sides of the
enclosure and must comply with the National
Electrical Code for installation of equipment in
hazardous areas (NEC Article 504, Intrinsically Safe
Systems ).
Connect the black wire (AC Hot) to terminal strip
J1-#3 on the CPU board located in the bottom of the
enclosure (shown below).
Figure 2-3. J1 Location on CPU Board
Connect the neutral wire (white) to terminal J1-#1,
and the ground wire (green) to terminal J1-#2. Use a
#16 AWG or smaller wire and strip approximately
3/16" and insert it beneath the compression plate in
the connector. Tighten the terminal with a screwdriver
and test the connection by pulling gently on the wire.
J1
GND PRINT K4 K3
K2
GND
NEUTRAL
117 VAC
TxD
RxD
PB
PB6
PB5
PB4
123
51617 18 19

12 EL232 XCPD Installation Manual
3.0 Indicator Setup
This section is provided to help the installer set up indicators to the EL232 XPCD.You must determine what
indicator will supply the data to the EL232 XPCD. Once this is determined, there are certain setup parameters
which you need to know depending on which indicator is chosen.
The EL232 XPCD supports the following scale formats and are listed in Table 3-1:
• UMC Series
• General Freedom I and II
• Electroscale 560
•A& D Instruments 4322, 4323, and 4316
•Weightronix WI-110 and WI-120
•Toledo indicators with “high speed data format”
• Flex-weigh DWM-4
•Analogic AN5315, AN5316, AN5322
• Masstron M-2500 and M-5000
•Fairbanks 90-164 series
• Streeter Richardson 9000
• Cardinal 738
• Instruments with programmable ASCII output
• Generic smart receiver mode
3.1 Serial Data Inputs
The EL232 XPCD can accept serial ASCII data sent in RS232C, 20 mA active, or 20 mA passive current loop
formats. These formats determine the electrical way that data is transmitted. The EL232 XPCD can read the data
transmission strings sent by 12 of the more popular scale indicator families as shown in Table 3-1. It cannot read
data from indicators not included in this list unless the formatting exactly matches one on the list (or if you have
a custom program).
Note:
Set up the EL232 XPCD on the bench with the indicator you intend to use before taking it to the installation site.
Brand Model Interface Baud Rate Data Format/Notes
Condec 1000 - 2000 series Continuous 1200 or 4800 See Figure 3-1
555/600/700 1200 to 9600
General Freedom Series I RS232 1200 to 9600 7 data bits, parity - odd,
Series II RS232
Electroscale 560 Current loop or RS232 in
continuous mode 1200 See Figure 3-2
A & D Instruments 4322, 4321, 4316 Current loop -passive or
RS232 2400 -
Weightronix 110 and 120 Current loop or RS232 1200 to 9600 -
Toledo - Current loop (active or
passive) 4800 -
Flex-Weigh DWM-4 - Current loop (active or
passive) 1200 to 9600 Data preamble - FF, FF, FF postamble FF FF 0A
Analogic AN5315, AN5316,
AN5322 Current loop or RS232 in continuous mode 1200 to 9600 See Figure 3-3
Table 3-1. Indicator Setup Parameters

Indicator Setup 13
Any device that has a programmable ASCII output can be used with the EL232 XPCD. Set the device to emulate
any of the following:
3.1.1 Condec Data Format
Figure 3-1 shows the Condec UMC series continuous output data format.
Figure 3-1. Condec Continuous Output Data Format
3.1.2 Electroscale Data Format
Figure 3-2 shows the Electroscale continuous output data format.
Figure 3-2. Electroscale Continuous Output Data Format
Masstron M2500, M5000 Continuous 4800 -
Fairbanks 90-164 Continuous current loop via
port C 1200 -
Streeter Amet 9000 Current loop 1200, 2400, 9600 -
Cardinal 738 Currentloop orRS232 using
S3=10000100 1200 to 9600 See Figure 3-4
Generic smart
receiver N/A RS232 or current loop 1200 to 9600 Can receive serial data ina wide variety of intuitive
formats. Use when all else
fails.
Brand Model Interface Baud Rate Data Format/Notes
Table 3-1. Indicator Setup Parameters (Continued)
<STX> <POL> <wwwwwww> <UNIT> <G/N> <S> <TERM>
STX (02h) Polarity:
<Space> = Positive
< – > = Negative
Weight: 7 digits, right-justified, dummy
zeroes, decimal point with no leading
zeroes except for leading zero
immediately preceding the decimal point.
Leading zeroes transmitted as spaces.
G = gram
K = kilogram
L = pound
T = ton (short)
<Space> = ton (metric),
grain, ounce or none
G for Gross
N for Net
Status:
<Space> = valid
I = Invalid
M = Motion
O = Over/under range
<CR> or
<LF> or
<CR> <LF>
<SOT> <R> <nnnnnnn> <EOT>
SOT (01h) “R” (52h)
Seven bytes of numeric data.
EOT (04h)

14 EL232 XCPD Installation Manual
3.1.3 Analogic Data Format
Figure 3-3 shows the Analogic continuous output data format.
Figure 3-3. Analogic Continuous Output Data Format
3.1.4 Cardinal Data Format
Figure 3-4 shows the Cardinal continuous output data format.
Figure 3-4. Cardinal Continuous Output Data Format
3.2 Serial Data Input
Some weight indicators have multiple outputs. Some can have two or more RS232 outputs or current loop
outputs which can be active or passive. The preferred interface is an active current loop output from the weight
indicator. A passive current loop is second in preference, and RS232 being the least desirable. The transmitted
data must be continuous and demand ports are unusable. Information is explained in further detail in the
following sections.
3.2.1 RS232 C
Data is transmitted as a voltage and alternates between +10VDC and -11 VDC. Hybrid RS232 signals can swing
between other voltage ranges as long as the positive swing is greater than 4 VDC and the negative is less than - 1
VDC. RS232 is ground referenced and therefore, connects the ground planes of the sending and receiving
instruments. RS232 should never be run more than 50 feet. It may work, but it may not work well or all the time.
Long RS232 data cables can act as a conduit for lightening or other electrical noise to the instrument. If you need
longer cable runs, use a 20 mA current loop.
STX (02h)
Net Weight: 9 characters, 7
active weight digits, no leading
zeroes, decimal point, negative
sign precedes first active digit.
Tare Weight: 9 characters, 7
active weight digits, no leading
zeroes, decimal point, negative
sign precedes first active digit.
<CR> or
<LF> or
<CR> <LF>
<STX> <nnnnnnnnn> <ttttttttt> <SP> <S> <UNIT> <SP> <TERM>
Status <S> is the sum of:
1 = In range
2 = Standstill
4 = Center of Zero
8 = Net mode
For example:
In range = 1
Standstill = 2
Net Mode = 8
<S> = B (hex)
0 = kilogram
1 = gram
2 = pound
3 = ton (short/metric)
4 = ounce
5 = none
6 = grain
Space
character Space character
<CR> <POL> <wwwwwww> <S> <SP> <UNIT> <SP> <G/N> <SP> <SP> <ETX>
Carriage
return
Polarity:
<Space> = Positive
< – > = Negative
Seven digits of weight data, including
decimal point. No leading zero
suppression.
G = gram
K = kilogram
L = pound
T = ton (short)
<Space> = ton (metric),
grain, ounce or none
G for Gross
N for Net
Status:
M = motion
O = out of range
<space> = for none
of the above
ETX (03h)
Space character (2)
Space
character
Space
character

Indicator Setup 15
Connect RS232 wiring as shown in Figure 3-5. Strip the wires approximately 3/16" and insert them into the
connectors as shown. Tighten the connectors and test the tightness by gently pulling on the wires.
Figure 3-5. RS232 C Input Hookup
The RS232 receiver in the EL232 XPCD is made from discrete components and requires a lower current than
most integrated circuit RS232 receivers. It is very difficult to damage and holds up under most conditions.
3.2.2 20 mA Active Current Loop Input
Data is transmitted as a current and is passed through an optical isolator. This current causes an LED to emit light
onto a photo transistor, which converts this light into a TTL signal. Current transmission can be made over long
distances and are quite immune from transient voltage or RFI/EMI noise. The distance a current loop can
transmit is limited by the voltage source available to the current loop and the speed of transmission which data is
sent. Normally a current loop should not send data at speeds greater than 4800 baud.
An active current loop means that the instrument which sends the data also supplies the voltage to power the
loop. This voltage can be as small as 5 VDC to as much as 24 VDC. When the loop goes through an optocoupler,
a drop occurs. This drop is about 2VDC. A current loop can power as many drops as there is voltage to power the
loop. For example, if a current loop is powered by 5VDC, it can normally drive two drops. If the same loop were
powered by 24 VDC, it could power about 11 remote displays or other devices.
Determine that your indicator has an active current loop and connect it as shown in Figure 3-6. Strip the wires
approximately 3/16" and insert them into the connector as shown. Tighten the connectors and test the tightness
by gently pulling on the wires.
Figure 3-6. 20 mA Active Current Loop Input Hookup
The 20 mA receiver in the EL232 XPCD is a HP-4200 and requires current swings of less than 4 mA as a mark
and greater than 12 mA for a space. The output of the HP-4200 is a TTL signal which appears at pin #7 of the
chip.
GND PRINT K4 K3 K2 K1 +5V CL4 IN- CL4 IN+ CL3 IN- CL3 IN+ CL2 IN- CL2 IN+ CL1 IN- CL1 IN+ CLO OUT- CLO OUT+
J2
RS232 (+)
GROUND
GND PRINT K4 K3 K2 K1 +5V CL4 IN- CL4 IN+ CL3 IN- CL3 IN+ CL2 IN- CL2 IN+ CLO OUT- CLO OUT+
J2
CL (+)
CL (-)
RS-232 (+)
RS-232 (-)

16 EL232 XCPD Installation Manual
3.2.3 20 mA Passive Current Loop Input
In this configuration, an external voltage or current source is connected to a current switch in the sending
instrument. Data is transmitted as a current and is passed through an optical isolator. This current causes an LED
to emit light onto a photo transistor, which converts this light into a TTL signal. Current transmission can be
made over long distances and are quite immune from transient voltage or RFI/EMI noise. The distance a current
loop can transmit is limited by the voltage source available to the current loop and the speed of transmission
which data is sent. Normally a current loop should not send data at speeds great than 4800 baud.
A passive current loop means that the instrument which sends the data does not supply the voltage to power the
loop. The voltage to power the loop must come from an external power supply or receiver. This voltage can be a
small as 5 VDC to as much as 24 VDC. When the loop goes through an optocoupler, a drop occurs. This drop is
about 2 VDC. A current loop can power as many drops as there is voltage to power the loop. For example, if a
current loop is powered by 5 VDC, it can normally only drive two drops. If the same loop were powered by 24
VDC, it could power about 11 remote displays.
The EL232 XPCD can supply power to a passive current loop. This voltage supplies about 8 VDC for use in the
loop.
Determine that your indicator has a passive current loop and connect it as shown in Figure 3-7. Strip the wires
approximately 3/16" and insert them into the connector as shown. Tighten the connectors and test the tightness
by gently pulling on the wires.
Figure 3-7. 20 mA Passive Current Loop Hookup
Note: The serial output is not available when using this input type without board modifications. Consult the factory for
details.
GND PRINT K4 K3 K2 K1 +5V CL4 IN- CL4 IN+ CL3 IN- CL3 IN+ CL2 IN- CL2 IN+
CLO OUT-
CLO OUT(+)
J2
CL (-)
CL1 (+)
RS-232 (+)
RS-232 (-)
Install this jumper