Flintec LDU 78.1 User Manual

Load Cell Digitizing Unit

Type LDU 78.1

TECHNICAL MANUAL

Firmware Version 78.183.v.2.50 or higher

Hardware Version 78.101.5.v.3.00

Document No. G119 Rev12 GB

Flintec GmbH Bemannsbruch 9 74909 Meckesheim

GERMANY www.flintec.com

Table of Contents:

1.	Safety Instructions ....................................................................................................................................			4
2.	Declaration of Conformity ........................................................................................................................			5
3.	Introduction and Specifications...............................................................................................................			6
4.	Communications and Getting started .....................................................................................................			7
4.1.	Serial Interface .........................................................................................................................................			7
4.2.	Command Language................................................................................................................................			7
4.3. Baud Rate / Device Address....................................................................................................................				8
4.4.	Getting Started .........................................................................................................................................			8
5.	Hardware and Wiring.................................................................................................................................			9
5.1.	Wiring		.......................................................................................................................................................	9
5.2. With Unit ........................................................................................................Adapter UA 77.1 (RS232)				9
5.3. With Unit ..............................................................Adapter UA 73.2 (RS422 / RS485 Full-/Half-Duplex)				9
5.4.	Terminal ...........................................................................................................................Configuration			10
5.5.	Load Cell .............................................................................................................................Connection			10
6.	Calibration ...................................................................................................and Calibration Sequence			11
7.	Commands ...........................................................................................................................– Overview			12
8.	Commands ..........................................................................................................................Description			14
8.1. System ..............................................................................Diagnosis Commands – ID, IV, IS, SR, RS				14
8.1.1.		ID ...................................................................................................................................	Get Device Identity	14
8.1.2.		IV ...............................................................................................................................	Get Firmware Version	14
8.1.3.		IS .....................................................................................................................................	Get Device Status	14
8.1.4.		SR .......................................................................................................................Reset LDU XX.X Firmware		14
8.1.5.		RS .................................................................................................................................Read Serial Number		14
8.2. Calibration .........Commands – CE, CM n, CI, MR, DS, DP, CZ, CG, ZT, FD, IZ, ZR, ZI, WT, TM, CS				15
8.2.1.		CE ..................................................................................Read TAC* Counter / Open Calibration Sequence		15
8.2.2.		CM ..................................................................................................................n Set Maximum Output Value		15
8.2.3.		CI .......................................................................................................................	Set Minimum Output Value	15
8.2.4.		MR .................................................................................................................Set Multi-range / Multi-interval		15
8.2.5.		DS ...............................................................................................................................Set Display Step Size		16
8.2.6.		DP .......................................................................................................................Set Decimal Point Position		16
8.2.7.		CZ ........................................................................................................................Set Calibration Zero Point		16
8.2.8.		CG .....................................................................................................................Set Calibration Gain (Span)		16
8.2.9.		ZT .................................................................................................................Enable / Disable Zero Tracking		16
8.2.10.		FD .............................................................................................................Reset to Factory Default Settings		17
8.2.11.		IZ ........................................................................................................................	Correction of System Zero	17
8.2.12.		ZR ..............................................................................................................................................Zero Range		17
8.2.13.		ZI ......................................................................................................................................	Initial Zero Range	17
8.2.14.		WT ..........................................................................................................................................Warm-up time		17
8.2.15.		TM ................................................................................................................................................Tare mode		17
8.2.16.		CS ........................................................................................................................Save the Calibration Data		18
8.3. Motion .................................................................................................Detection Commands – NR, NT				18
8.3.1.		NR ...............................................................................................................................Set No-motion Range		18
8.3.2.		NT ......................................................................................................................Set No-motion Time Period		18
8.4. Filter Setting .................................................................................................Commands – FM, FL, UR				19
8.4.1.		FM ...............................................................................................................................................Filter Mode		19
8.4.2.		FL ............................................................................................................................................Filter Settings		19
8.4.3.		UR .....................................................................................................................Update Rate and Averaging		20

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	8.5. Taring and Zeroing Commands – SZ, ZA, RZ, ST, RT..........................................................................			21
	8.5.1.	SZ Set System Zero.......................................................................................................................................		21
	8.5.2.	ZA Set Averaged System Zero.......................................................................................................................		21
	8.5.3.	RZ Reset Zero................................................................................................................................................		21
	8.5.4.	ST Set Tare....................................................................................................................................................		21
	8.5.5.	RT Reset Tare................................................................................................................................................		21
	8.6. Output Commands – GG, GN, GT, GS, GW, GA, GL, OF ....................................................................			22
	8.6.1.	GG Get Gross Value ......................................................................................................................................		22
	8.6.2.	GN Get Net Value ..........................................................................................................................................		22
	8.6.3.	GT Get Tare Value.........................................................................................................................................		22
	8.6.4.	GS Get ADC Sample Value ...........................................................................................................................		22
	8.6.5.	GW Get Data String “Net, Gross and Status“.................................................................................................		22
	8.6.6.	GA Get Triggered Average Value ..................................................................................................................		22
	8.6.7.	GL Get Data String “Average, Gross and Status“ ..........................................................................................		23
	8.6.8.	OF Output Format for Data String GW and GL ..............................................................................................		23
	8.7. Auto–transmit Commands – SG, SN, SX, SW, SA, SL .........................................................................			24
	8.7.1.	SG Send Gross Value continuously ...............................................................................................................		24
	8.7.2.	SN Send Net Value continuously ...................................................................................................................		24
	8.7.3.	SX Send ADC Sample Value continuously ....................................................................................................		24
	8.7.4.	SW Send Data String “Net, Gross and Status“ continuously..........................................................................		24
	8.7.5.	SA Send Triggered Average Value automatically ..........................................................................................		24
	8.7.6.	SL Send Data String “Average, Gross and Status“ automatically ..................................................................		24
	8.8. Commands for External I/O Control – IN, IO, IM ...................................................................................			25
	8.8.1.	IN	Read the Status of the Input Channels .....................................................................................................	25
	8.8.2.	IO	Read / Set the Status of the Output Channels..........................................................................................	25
	8.8.3.	IM	Control of the logic outputs by the host application ..................................................................................	25
	8.9. Setpoint Output Commands – Sn, Hn, An .............................................................................................			26
	8.9.1.	S n Setpoint Value .........................................................................................................................................		26
	8.9.2.	H n Setpoint Hysteresis and Switching Action................................................................................................		26
	8.9.3.	A n Allocation of Gros or Net Value................................................................................................................		26
	8.10.	Communication Setup Commands – AD, BR, DX, TD, OP, CL.........................................................		27
	8.10.1.	AD Device Address ........................................................................................................................................		27
	8.10.2.	BR Baud Rate ................................................................................................................................................		27
	8.10.3.	DX Half-duplex or Full-duplex ........................................................................................................................		27
	8.10.4.	TD Transmission Delay ..................................................................................................................................		27
	8.10.5.	OP Open Device ............................................................................................................................................		27
	8.10.6.	CL Close Device Address n ...........................................................................................................................		27
	8.11.	Save Calibration and Setup Data Commands – CS, WP, SS, GI, PI ................................................		28
	8.11.1.	WP Save the Setup Parameters ....................................................................................................................		28
	8.11.2.	SS Save Setpoint Parameters........................................................................................................................		28
	8.11.3.	GI Save an Image File from the EEPROM ....................................................................................................		28
	8.11.4.	PI Download an Image File to the EEPROM.................................................................................................		28
	8.12.	Trigger Commands – SD, MT, GA, TE, TR, TL, SA...........................................................................		29
	8.12.1.	SD Start Delay Time.......................................................................................................................................		29
	8.12.2.	MT Measuring Time .......................................................................................................................................		29
	8.12.3.	GA Get Triggered Average Value ..................................................................................................................		29
	8.12.4.	TE Trigger Edge.............................................................................................................................................		29
	8.12.5.	TR Software Trigger.......................................................................................................................................		29
	8.12.6.	TL Trigger Level .............................................................................................................................................		30
	8.12.7.	SA Send Triggered Average Value automatically ..........................................................................................		30
	8.13.	Re-Trigger Commands – RW, TT, TS, DT, TW, TI, HT .....................................................................		31
	8.13.1.	RW Trigger Window for Re-Trigger Function .................................................................................................		31
	8.13.2.	TT Averaging Time for Re-trigger Function ....................................................................................................		31
	8.13.3.	TS Stop Value for Re-trigger Function ...........................................................................................................		31
	8.13.4.	DT Short-time Averaging Period ....................................................................................................................		31
	8.13.5.	TW Window for Automatic Taring...................................................................................................................		31
	8.13.6.	TI	Averaging Time for Automatic Taring........................................................................................................	32
	8.13.7.	HT Hold time for Violation of Setpoint Limit....................................................................................................		32
9.	Use in “Approved” Applications............................................................................................................			33
10. Updates – Firmware Download ..............................................................................................................				34

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RIGHTS AND LIABILITIES

All rights reserved.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of Flintec GmbH

No patent liability is assumed with respect to the use of the information contained herein. While every precaution has been taken in the preparation of this book, FLINTEC assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.

The information herein is believed to be both accurate and reliable. FLINTEC, however, would be obliged to be informed if any errors occur. FLINTEC cannot accept any liability for direct or indirect damages resulting from the use of this manual.

FLINTEC reserves the right to revise this manual and alter its content without notification at any time.

Neither FLINTEC nor its affiliates shall be liable to the purchaser of this product or third parties for damages, losses, costs, or expenses incurred by purchaser or third parties as a result of: accident, misuse, or abuse of this product or unauthorized modifications, repairs, or alterations to this product, or failure to strictly comply with FLINTEC operating and maintenance instructions.

FLINTEC shall not be liable against any damages or problems arising from the use of any options or any consumable products other than those designated as Original FLINTEC Products.

NOTICE: The contents of this manual are subject to change without notice.

Copyright © 2010-2011 by Flintec GmbH, 74909 Meckesheim, Bemannsbruch 9, Germany

1.Safety Instructions

CAUTION READ this manual BEFORE operating or servicing this equipment. FOLLOW these instructions carefully. SAVE this manual for future reference. DO NOT allow untrained personnel to operate, clean, inspect, maintain, service, or tamper with this equipment. ALWAYS DISCONNECT this equipment from the power source before cleaning or performing maintenance. CALL FLINTEC ENGINEERING for parts, information, and service.

WARNING ONLY PERMIT QUALIFIED PERSONNEL TO SERVICE THIS EQUIPMENT. EXERCISE CARE WHEN MAKING CHECKS, TESTS AND ADJUSTMENTS THAT MUST BE MADE WITH POWER ON. FAILING TO OBSERVE THESE PRECAUTIONS CAN RESULT IN BODILY HARM.

WARNING FOR CONTINUED PROTECTION AGAINST SHOCK HAZARD CONNECT TO PROPERLY GROUNDED OUTLET ONLY. DO NOT REMOVE THE GROUND PRONG.

WARNING DISCONNECT ALL POWER TO THIS UNIT BEFORE REMOVING THE FUSE OR SERVICING.

WARNING BEFORE CONNECTING/DISCONNECTING ANY INTERNAL ELECTRONIC COMPONENTS OR INTERCONNECTING WIRING BETWEEN ELECTRONIC EQUIPMENT ALWAYS REMOVE POWER AND WAIT AT LEAST THIRTY (30) SECONDS BEFORE ANY CONNECTIONS OR DISCONNECTIONS ARE MADE. FAILURE TO OBSERVE THESE PRECAUTIONS COULD RESULT IN DAMAGE TO OR DESTRUCTION OF THE EQUIPMENT OR BODILY HARM.

CAUTION OBSERVE PRECAUTIONS FOR HANDLING ELECTROSTATIC SENSITIVE DEVICES.

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2.Declaration of Conformity

0 EG-Konformitätserklärung

EC-Declaration of Conformity

Monat/Jahr: month/year:	11/2010
Hersteller: Manufacturer:	Flintec GmbH
Anschrift: Address:	Bemannsbruch 9
	D-74909 Meckesheim
	Deutschland / Germany
Produktbezeichnung: Product name:	LDU 78.1

Das bezeichnete Produkt stimmt mit folgenden Vorschriften der Europäischen Richtlinien überein:

This product confirms with the following regulations of the Directives of the European Community

Richtlinie 2004/108/EG des Europäischen Parlaments und des Rates vom 15. Dezember 2004 zur Angleichung der Rechtsvorschriften der Mitgliedstaaten über die elektromagnetische Verträglichkeit und zur Aufhebung der Richtlinie 89/336/EWG

Richtlinie 2006/95/EG Niederspannungs-Richtlinie

Die Absicherung aller produktspezifischen Qualitätsmerkmale erfolgt auf Basis eines zertifizierten Qualitätsmanagement-Systems nach DIN ISO 9001.

Diese Erklärung bescheinigt die Übereinstimmung mit den genannten Richtlinien, beinhaltet jedoch keine Zusicherung von Eigenschaften.

Directive 2004/108/EC of the European Parliament and of the Council of 15th December 2004 on the approximation of the laws of the Member States relating to electromagnetic compatibility and repealing Directive 89/336/EEC

Directive 2006/95/EC Low Voltage Directive

All product-related features are assured by a quality system in accordance with ISO 9001.

This declaration certifies the conformity with the listed directives, but it is no promise of characteristics.

Folgende Normen werden zum Nachweis der Übereinstimmung mit den Richtlinien eingehalten:

As a proof of conformity with the directives following standards are fulfilled:

OIML R-76-1

DIN EN 45501

Nicht-Selbsttätig Waagen – Metrologische und technische Anforderungen (OIML R-76:2002 Teil 1)

Non-automatic weighing systems – Metrological and technical requirements (OIML R-76:2002 Part 1)

Metrologische Aspekte nichtselbsttätiger Waagen; Deutsche Fassung EN 45501:1992

Anhang B.3: Funktionsprüfungen unter Störeinflüssen

Anhang C: Verfahren für die Prüfung derStörfestigkeit gegen hochfrequente elektromagnetische Felder.

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3.Introduction and Specifications

The model LDU 78.1 is a very precise high-speed digital amplifier for weighing and force measurements with strain gauge (SG) sensors. The LDU 78.1 can be used in legal for trade as well as for industrial applications. The device features full multi-drop communications capability and can be programmed via a straightforward ASCII command set.

The LDU XX.X series and the amplifier DAS 72.1 with on-board digital display, use the same command set. You can connect up to 32 SG amplifiers of either the LDU XX.X series or DAS 72.1 type onto a single RS 485 bus. The LDU 78.1 with its accurate A to D converter and an internal sample rate of up to 2400 measurement values per second, is particularly suitable for static or dynamic measurements and control purposes.

	LDU 78.1 Specifications
	Accuracy class	III
	Test certificate according OIML R76	10 000 intervals and n x 10 000 intervals (n = 2, 3 …)
	Linearity	< 0.002 % FS
	Excitation	5 V DC, for load cells > 350 Ohm ( > 87,5 Ohm at supply voltage
		up to max. 14 V DC); 6 wire technique
	Analogue input range	±11 mV (bipolar; for weighing applications, force and torque
		measurements)
	Minimum input sensitivity	0.05 μV/d
	Certified accuracy according OIML R 76	0.3 μV/vsi
	Resolution	± 260 000 counts (input); ± 100 000 counts (output)
	Conversion rate	2400 values/second internal, up to 600 values/second external
	Digital filter	FIR Filter 2.5 to 19,7 Hz or IIR Filter 0.25 to 18 Hz;
		Each in 8 steps adjustable
	Calibration	By software via ASCII commands, sehr einfach durchführbar
	Communication interface	RS485 oder RS422; Voll-Duplex oder Halb-Duplex;
		9600 ... 115200 Baud; busfähig bis zu 32 Einheiten
	Standard weighing functions	Gross, tare, net, zero, etc.
	Digital inputs	2x opto-isolated inputs, 10 ... 30 V DC max. 3 mA,
		Status via software
	Digital outputs	2x open collector outputs, < 30 V DC, max. 200 mA
	Temperature effect on zero	Typical < 5 ppm/°K; max. < 7 ppm/°K
	Temperature effect on span	Typical < 4 ppm/°K; max. < 6 ppm/°K
	Temperature range	–15 °C to +55 °C (operation); –30 °C to +70 °C (storage)
	Enclosure	Tinned steel enclosure, IP20 protection,
		special IP65 housing on request
	Dimensions and weight	82 x 31 x 6 mm, weighs approx. 30 g;
		with adaptor board 99 x 41 x 12 mm, approx. 50 g
	Power supply	12 ... 24 V DC ±10 %, < 60 mA, not galvanically isolated
	Available accesoires	Adaptor board UA73.2 (RS485 / RS422) or
		Adaptor board UA77.1 (inkl. converter RS422/RS232)
	EMC	OIML R-76:2006 and DIN EN 45 501:1992/AC1993

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4.Communications and Getting started

4.1.Serial Interface

Communicating with the LDU 78.1 digitizer is carried out via the RS422/RS485 port. The data format is the familiar 8/N/1 structure (8 data bits, no parity, 1 stop bit).

Available baud rates via the RS422/RS485 port are as follows: 9 600, 19 200, 38 400, 57 600 or 115 200 baud.

RS422:

Connection using a 4 wire technique

Point-to-Point connection, i.e. no bus communication possible

Half duplex setup (DX=0)

RS485:

Connection using 2- or 4-wire techniques

Multi-drop connection possible, up to 32 LDU XX.X

Half or Full Duplex (DX=0 or DX=1) possible

(RS232):

The optional adapter board UA 77.1 is available which has an RS485/RS232 converter built in.

4.2.Command Language

The command set of LDU XX.X series is based on a simple ASCII format (2 capital letters). This enables the user to setup the device, get results or check parameters.

Example: LDU XX.X with the address or channel number 1 is connected via the RS 485 port to a bus system. You want to get the net weight.

In this manual means: Space “_“ and Enter (CR/LF) ““
Master (PC / SPS) sends	Slave (LDU XX.X) responds	Meaning
OP 1		Open device #1
	OK	Device # 1 ready
GN		Get net weight
	N+123.45	Net weight with algebraic sign / floating point

The command OP_2 opens the communication channel to LDU XX.X device #2. Now device #2 acknowledges that it is active and responds to any commands on the bus. Communication with device #2 will be closed by another OP command (for another device on the bus e.g. OP_5) or by the command CL_2.

Each OP_X command implies a CL command to all other devices on the bus except device #X. This makes the address structures easier and the system performance improves.

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4.3.Baud Rate / Device Address

Baud Rate:

For baud rate setup use command BR, see chapter 8.10

Factory default: 9 600 baud

Device Address:

For address setup use command AD, see chapter 8.10

Factory default: Address 0

Setting the device address to 0 will set the continuously active mode, where the device becomes permanently active, and will listen and respond to any command on the bus, without the need for an OP xxx command.

Note: The LDU XX.X series has sets of special solder pads on the under side of the PCB (see chapter 5.1). If the solder pads are bridged then the LDU will be in a special configuration mode to set up the baud rate and device address. This function should be used only when baud rate or address is unknown.

After power up, the LDU XX.X will enter a special baud rate search mode – waiting for a space character (0x20) to be received. The time duration of this character is measured by the LDU and its baud rate timing will be set accordingly – i.e. the baud rate of the terminal used will be the baud rate used by the LDU subsequently. The device address will also be set to ”0“

4.4.Getting Started

You will require:

PC or PLC with either a RS422 or RS485 communication port

If using a PC / PLC with RS232 port, a RS422/485 to RS232 converter will be required (option UA 77.1)

Interconnecting cabling - confirm that all relevant pins are used – see the wiring diagram at the end of this section

A load cell / scale with test weights or a load cell simulator

A 12-24 VDC power supply capable of delivering approximately 100mA for each LDU and load cell

One or more LDU 78.1

A suitable ASCII communication software *

Refer to the following wiring diagram in chapter 5.

* You can easily communicate between a PC and an LDU using programs such as Procomm, Telemate, Kermit or HyperTerminal (included in Windows).

Also the DOP software with graphical user interface and oscilloscope function, running under Windows 2000/XP is available as freeware. This software is included on the Flintec product CD-ROM (2008 or later).

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5.Hardware and Wiring

5.1.Wiring

5.2.With Unit Adapter UA 77.1 (RS232)

5.3.With Unit Adapter UA 73.2 (RS422 / RS485 Full-/Half-Duplex)

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5.4.Terminal Configuration

LDU 78.1		UA 73.2		UA 77.1		Function
Pin no.
0		Gnd (Shield)		Gnd (Shield)		Common Ground
1		+Exc		+ Exc		+ Excitation for load cell
2	+ Sens			+ Sens		+ Sense for load cell
3	+ Sig			+ Sig		+ Signal
4		– Sig		– Sig		– Signal
5		– Sen		– Sen		– Sense for load cell
6		– Exc	– Exc		– Excitation for load cell
7		Gnd	Gnd		Signal ground / 0 V DC
8		NC	NC		Not connected
9		NC	NC		Not connected
10		+ Rx	RxD (RS232)		Receive
11	- Rx		Gnd (RS232)		UA 73.2: Receive / UA 77.1: Common ground RS232
12	- Tx		Gnd (RS232)		UA 77.1: Senden / UA 77.1: Common ground RS232
13		+ Tx		TxD (RS232)	Transmit
14		0 In		0 In		Digital input 0 (with reference to ground)
15		0 out		0 out		Digital output 0 (with reference to ground)
16		1 In		1 In		Digital input 1 (with reference to ground)
17		1 Out		1 Out		Digital output 1 (with reference to ground)
18	+ PWR		+ PWR		Power supply 12...24 V DC
19		Gnd		Gnd		Common ground / 0 V DC

Remarks:

UA 73.2 (see chapter 5.3) is prepared for full-duplex operation

Valid for half-duplex operation: pin no. 10 + 13 = A and pin no. 11 + 12 = B

UA 77.1 with integrated RS422/RS232 converter (see chapter 5.2)

5.5.Load Cell Connection

The load cell wiring should be made carefully before energizing to avoid damages to the amplifier and the load cells. The input resistance of the load cells that you want to connect should be more than 250 Ω.

The sense pins of the instrument should be connected. In 4-wire installations the switches SW1 and SW2 (see chapter 5.1) have to be short circuited.

Flintec load cell; 4 wire connection

Flintec load cell; 6 wire connection

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6.Calibration and Calibration Sequence

The calibration of LDU 78.1 is only possible after starting a calibration sequence (compare with chapter 8.2).

	Command CE:	Calibration enable – returns the current TAC value
Command CM1 / CM2 /CM3:		Calibrate maximum display – sets the max. allowable display value
	Command CI:	Calibrate minimum – sets the minimum allowable display value
	Command MR:	Multi-range / Multi-interval
	Command DS:	Display step size – sets the output incremental step size
	Command DP:	Decimal point – sets the position of the output decimal point
	Command CZ:	Calibrate zero – sets the system zero point
	Command CG:	Calibrate gain – sets the system gain
	Command ZT:	Zero track enable / disable
	Command IZ:	If applicable: Correction of System Zero
	Command ZR:	If applicable: Zero Range – sets the zero range manually
	Command ZI:	If applicable: Initial Zero Range
	Command WT:	If applicable: Warm-up time
	Command FD :	If applicable: Reset to factory default settings
	Command CS :	Save calibration data (TAC counter automatically incremented by 1)

Preparing the calibration:

Check, if the max value of the display is set sufficiently high (see chapter 8.2: command CM n)

Check, if the no motion conditions are defined reasonable (chapter 8.3: e.g. NR = 1, NT = 1000)

Set the IIR filter frequency to 0.5 Hz (see chapter 8.4: FM = 0, FL = 7)

Example: Setup of zero point, system gain and decimal point

The chosen calibration weight has the value 5000 (increments). That could be 500 g, 5 kg or 5000 kg. We calibrate with 500 g. The decimal point is set up by command DPx (x = 1, 2 or 3), here 1 figure after the decimal point. A measured weight of 500 g is displayed as 500.0.

Master (PC / SPS) sends	Slave (LDU XX.X) responds	Meaning
CE	E+00017 (example)	Request: TAC counter CE17
Adjust zero: The scale has to be empty. No load!
CE 17	OK	Calibration sequence active
CZ	OK	System zero point saved
Adjust gain:	First put the calibration weight on	the scale (here 500 g)!
CE 17	OK	Calibration sequence active
CG 5000	OK	Setting span
CG	G+05000	Request: span 5000 d
CE 17	OK	Calibration sequence active
DP 1	OK	Setting: decimal point 0000.0
CE 17	OK	Calibration sequence active
CS	OK	Save calibration data in EEPROM

Zero point, gain and decimal point position were saved in the EEPROM; the calibration counter (TAC) is increased automatically by 1.

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