LDM User Manual.book - MICRO-AIDE
Contents
1. Multi drop Network Accessing the VEL PCR acs cog oe ewes ee ERR RSS PS User Configured Saar ate A Rev and Xmt Terminations 1 and 2 Enable Xmt Channel Busy Detector RS 232 Protective Ground 5 RIS to CIS Delay SW2 owe yx Sed ew es Equalization SW3 s at hh hm nn Permanently Asserting the 5 WAS X3 ces e ee de be de rca dy tees LDM 1 Standalone 2 LOVE rs a A Go dE RR LDM 16 1222 ded UR menaa sati Had eee Attaching the Network Lines ee Connecting tothe DTE OPERATION LDM User Manual Select Mode Pushbutton 20 OpetatineMod s ss aos Soa Goa ROSE See be 20 Normal xs Bd E ES 21 Test Mode A Analog test with digital loop 22 Test Mode B Analog loop back with DTE data 22 Test Mode C Analog loop back with test data 23 CHAPTER 4 MAINTENANCE InttOdUCHOB y ica ee e dU X S S EU 25 PCB Removal and Insertion 25 Jumper and Switch Locations 26 Trouble Shooting Guide ee 27 AP2. FRONT PANEL LDM 16 Limited Distance Modem CTS OO RTS Rev OO Xmt Select Modo o Eq 1 MicRO AiDE MICRO AIDE CORPORATION ED COVINA CA Figure 2 LDM 16 Nest The LDM 1 standalone and LDM 16 nest are packed in individual containers that are properly sized for the unit The LDM 1 plug in PCBs are secured inside the LDM 16 nest Abundant packing materials are provided to mini mize mechanical shock to the contents Before opening the shipping carton inspect the carton for damage Damage to the container should be noted Carefully remove the unit It is advisable to save all packing materials in the event the unit ever needs to be returned to MICRO AIDE Inspect each unit and PCB for any visual damage The unit should not be scratched dented or deformed in any way If it appears that the unit was dam aged in shipment the responsible carrier should be notified immediately MICRO AIDE will assist the user in filing a claim in the event damage was sustained during shipment LDM User Manual LDM 1 Basics The LDM 1 can be thought of as a device that extends the distance that RS 232 serial data can be transmitted and received It does so over fout wire two pair private line networks It includes a standard DB 25 female con nectot that allows for direct connection to any DTE device The LDM 1 is configured as a DCE device Refer to Figure 7 on page 31 Regardless of the network configuration refer
3. Off Test Mode A Off amp On Test Mode B On amp On Test Mode C CTS Clear to Send Amber DTE can send data RTS Request to Send Amber DTE has asserted RTS Rcv Receive Data Red Receive channel is receiving data Xmt Transmit Data Red Transmit channel is transmitting data the operating mode of the LDM 1 The Normal Mode of operation occurs automatically when the unit is first powered up By momentarily pressing the Select Mode pushbutton switch the modem can be advanced from Normal Mode to Test Mode A Test Mode B Test Mode C and finally back to Nor mal Mode Each time the pushbutton switch is pressed the modem advances one step in the cycle OPERATING MODES Each of the four operating modes are described in the following sections Figure 6 on page 21 illustrates the signal flow applicable to each operating mode NOTE Regardless of the operating mode selected the transmit and receive channels will remain terminated in accordance with the user s selections 20 Operation Operating Modes NORMAL MODE TEST MODE Xmt 1 Xmt Channel Channel Transmitter Decoders Decoders Rev Rev Channel Channel Receiver Receiver TEST MODE TEST MODE C Xmt Xmt Channel Channel Decoders Rev Rev Channel Channel Receiver Receiver Figure 6 Test Mode Signal Flow NORMAL MODE Normal Mode is automatically selected when the LDM 1 is powered up The modem will transmit receive data to from th
4. On Off AX5 E Protective Gnd AX3 xmt Busy Detector AX2 EE xmt Term Equalization AX1 SW3 Rev Term Figure 5 LDM 1 PCB SETUP In the sections that follow a description is provided for each jumper and switch setting description of how to permanently assert the modem s RTS signal is also provided RCV AND XMT TERMINATIONS AND AX2 AX1 and AX2 allow the user to select either a 150Ohm On or high imped ance Off termination These jumpers used in accordance with the fol lowing rules The AX1 Rev and AX2 Xmt settings must always match each other Irrespective of the type of network always terminate the extreme ends of the network i e the near and far ends 13 LDM User Manual If two modems located at an end point in the network only one modem should be terminated Never terminate modem located at a drop point There should never be more than two terminations per network channel CAUTION Failure to provide the correct termination and Equalization set tings can result in significant communication errors ENABLE XMT CHANNEL Busy DETECTOR AX3 The LDM 1 has a built in carrier detector for its transmit channel When enabled the LDM 1 will not assert its CTS signal until it verifies that a carrier is no longer present at the transmit channel This feature prevents two modems from attempting to transmit simultaneously To enable the busy detector
5. default On On Short 2 Off On Mid range 3 On Off Mid range 4 max Off Off Long On down Off up Table 2 Equalization Settings Selecting the proper Equalization setting relates directly to cable length and wire diameter The higher settings are used when the master and slave modems ate separated by a greater distance and or a smaller wire diameter is employed Table 6 on page 31 includes a list of suggested Equalization set tings The factory default Equalization setting is 1 i e minimum PERMANENTLY ASSERTING THE RTS The LDM 1 can be used with DTE interfaces that lack RTS and CTS signals provided the modem s use is limited to point to point networks or as a master in a multi drop network For these applications the DTE to modem cable must include a jumper between pins 4 RTS and 6 DSR at the LDM 1 end This technique will force the modem s RTS to be constantly asserted Figure 7 on page 31 illustrates the pin assignments used by the LDM 1 s DB 25 con nector INSTALLATION Physical installation of the modems and nests can be performed after the con figuration settings are in place LDM 1 STANDALONE The standalone version LDM 1 can be placed in any convenient location It generates very little heat and utilizes no hazardous voltages desktop or shelf within several feet of the network lines is perfectly satisfactory as a 15 LDM User Manual mounting location The standalone modem comes equipped with four
6. provided by the DTE The transmit and receive channels are left terminated but are discon nected from the test data 1 test data is not sent to the network In Test Mode B the Tst2 and Tst1 LEDs will be off and on respectively The CD indicator will be off The RTS and CTS indicators will be either on or off depending upon the status of the DTE The Rcv and Xmt indicators will illu minate when data is being received and transmitted respectively The RTS sig nal does not need to be asserted in this test mode Test Mode B 15 useful in checking major elements of the modem and DTE interface TIP Test Mode requires an equalization setting of 1 i e minimum 22 Operation Operating Modes TEST MODE C ANALOG LOOP BACK WITH TEST DATA Test Mode C also loops the transmit channel s analog output signal to the input of the receive channel However the transmitted data is provided by an on board test data generator The test data consists of alternating mark and space bits The test data has a Baud rate of 19 200 The receive and transmit channels are left terminated but ate disconnected from the test data i e test data is not sent to the network In Test Mode C the Tst2 and Tst1 LEDs are both on The CD LED will flash as an indication that the test data is being received properly The RTS CTS and Xmt indicators will illuminate depend ing upon the status of the DTE interface However these signals are ignored in T
7. the TxDOT provided TMS Version 2 2 EEPROM One master LDM 1 that will be connected to the PC running CTSCU exe One slave LDM 1 fot each LCU e two pair cable connecting the LDM 1s in either a point to point or multi drop network configuration One 9 pin female to 25 pin male serial communications cable to be con nected between the master LDM 1 and the comm port of the PC A DB 25 male to DB 25 male cable wired one to one that will connect each slave LDM 1 to each LCU INSTALLATION With power off to all of the equipment items do the following 35 LDM User Manual 1 The Rev and Xmt Termination settings for the near end master and far end slave modems must be set to On The termination settings for all other modems must be set to Off 2 Connect the PC s serial comm port to one end of the serial comm cable Connect the other end to the DTE port of the master LDM 1 3 Connect the Xmt and Rev and pins of each modem to the network cable 4 Connect the port of each slave modem to the RS 232 port of the labeled Communications 5 Install the TMS 2 2 EEPROM into the CPU PCB of each LCU 6 Set the Unit ID of the first LCU to 1 Set the Unit ID of additional LCUs to 2 3 etc 7 Apply power to all equipment items 8 Launch the CTSCU exe software in the PC 9 Verify the test LEDs of each modem off 10 Verify the RTS and CTS LEDs are on at the master and o
8. the nest Remove the plug in PCB by depressing the PCB retainer at the bottom front edge of the nest while rotating the PCB s card ejectot upward CAUTION Electrostatic discharges can cause serious damage to electronic components Normal anti static precautions are recommended when han dling the LDM 1 PCB USER CONFIGURED SETTINGS Two switch assemblies and four jumpers comprise the collection of user con figured settings Table 1 provides a brief definition of each setting Also included in Table 1 are the factory default settings Label Description Position Setting Default Setting Receive channel termination On or Off On 150 Ohms AX2 Transmit channel termination On or Off On 150 Ohms AX3 Transmit channel busy detector On or Off Off disabled AX5 RS 232 protective ground On or Off Off isolated SW2 RTS to CTS delay msec 64 32 16 msec SW3 Receive channel Equilization see below Minimum Table 1 User Configured Settings 12 Setup and Installation Setup The factory default switch and jumper settings for AX1 through AX5 and SW2 satisfactory for use with a point to point network The Equal ization setting controlled by SW3 may need to be changed as required by the length of cable being used Figure 5 illustrates the location of each setting on the LDM 1 PCB CTS RTS Delay PARA SW2 Jumper Jumper
9. vibra tion absorbing rubber feet It is powered by a 24 Vac wall mount transformer included with the LDM 1 standalone Nearby access to 120 Vac power is required The female connector of the transformer plugs directly into the round male connector located at the rear panel of the modem Refer to Figure 1 on page 6 The modem is always on when power is connected NOTE The ambient operating temperature of the all LDM products is 4 F 20 C to 158 F 70 LDM 1 PLUG IN The user may find it necessary to install the correct complement of PCBs into the LDM 16 before the nest can be used LDM 1 plug in PCBs are installed by unfastening the front cover of the nest depressing the PCB retainer bar and inserting the PCB into the plastic card guides The PCB should be pushed as far forward as possible The retainer bar should then spring back locking the PCB in place If fewer than nine modems are being installed it is recom mended that an empty slot be left between adjacent PCBs It may be necessary to remove the plastic shield that covers the rear connector cut outs before the PCB can be inserted Spare plastic shields should be used to cover any vacant cut outs The nest is equipped with a 120 to 24 Vac transformer The 24 Vac power source must be connected to each PCB Use the connector harness provided for this purpose It can be used to daisy chain as many as eight PCBs together Additional connectors can be easily attach
10. LIMITED DISTANCE MODEM USER MANUAL by MICRO AIDE CORP LIMITED DISTANCE MODEM USER MANUAL A comprehensive document for the following LDM products e LDM 1 standlalone e LDM 1 plug in LDM 16 nest NA Revised August 6 2009 CORP 626 915 5502 support micro aide com Copyright 2007 by MICRO AIDE Corporation All rights reserved No part of this document may be reproduced or transmitted in any form by any means without the written permission of MICRO AIDE Corporation The information in this document is subject to change without notice MICRO AIDE believes the information contained in this document to be accurate However MICRO AIDE assumes no responsibility for any errors or omissions Windows Windows 98 and Windows XP are registered trademarks of Microsoft Corporation CHAPTER 1 CHAPTER 2 CHAPTER 3 TABLE OF CONTENTS GENERAL DESCRIPTION s vts s Bok Bd al ee ee AUN Key av pa a weed el wh ee ie About This Manual s s sss s e mi oes ek BE eo Revision Level a TxDOT SETUP AND INSTALLATION Introduction e tee pen Mk Pew oe Hea aes Basics bee a Network Types s s Wr AS E ee Re WR REA Poi t to POIBE
11. PENDIX TECHNICAL DATA LDM 1 Specifications 29 LDM 16 Specifications o o o 30 Transmission Range Specifications o o 30 Recommended Equalizations Settings 31 DB 25 Connector Wiring e 31 APPENDIX TXDOT APPLICATIONS Introduction 4 25 EEA SS SORES 33 Network Configurations 33 Point to Point ae a ee 33 Multi lt seco E P das or ek ee 34 222 Cables SS deb 34 ECU te Pa Ga 34 PSOM to LDM I Ee PEE P 34 ADU to LDM L wc 34 Test 4 4608 deg Bo A Rd OY 35 Requitements sa sia ee o RR a 35 4 sa desea Ae AR e ne OS 35 Test Procedures woo y da ee ea BAG RA e 36 1 GENERAL DESCRIPTION INTRODUCTION MICRO AIDES family of Limited Distance Modem LDM products can be used in a variety of data communications applications The family consists of the following products LDM 1 standalone complete LDM photographed on the cover page of this manual LDM 1 plug in functionally identical to the standalone version it is a printed circuit board PCB that is mounted within
12. and Accept the default parameters as listed below 8 lt PgUp Dn CHANNEL CTRL ENTER 5 Execute the Statistics gt Reset Statistics File Execute the Error gt Reset Error Log File command 6 Execute the Control gt Reset All LCUs command After a brief delay a message will indicate that the reset was successful 7 Execute the Control gt Download LCU Code to All LCUs command After a brief delay a message will indicate that the download was successful 8 Start the test at 9600 Baud by executing the Begin command Highlight the command and then press the Enter key twice The test will start A display similar to the following will appear 38 TxDOT Applications Test Software E 1 RONGAR 11MYDO i ch Data The test will run continuously until it is stopped by pressing the Esc key The number of test blocks and errors by type will be reported Run the test in accordance with the TxDOT acceptance criteria 39 LDM User Manual USER NOTES 40 Material Return Policy In the event the customer identifies a malfunction in any product call or write MICRO AIDE and obtain a Return Material Authorization RMA number from the customer service depart ment Return the product to MICRO AIDE freight prepaid with a note in warranty repair a purchase order out of warranty for the repair listing the following information RMA number from MICRO AIDE Return shipment address Name and telep
13. ce Enabled 150 Disabled gt 40KOhm Carrier Detection If enabled checks for absence of signal on Xmt channel before asserting CTS Isolation Fully isolated from power and DTE interface MICRO AIDE reserves the right to make changes at its sole discretion to any specification listed herein drop network configurations limited to no more than eight modems The transmission distances listed refer to the cable length measured from end master modem to far end slave modem Baud Rate 19AWG 22 AWG 24AWG bps miles 2400 30 16 12 4800 25 13 10 9600 20 11 8 19 200 13 8 6 30 AAA O Ao S Table 5 Cable Length vs Baud Rate and Cable Diameter Technical Data Recommended Equalizations Settings RECOMMENDED EQUALIZATIONS SETTINGS The Equalization settings listed in Table 6 are for approximation purposes only The optimum setting will vary from network to network The transmis sion distances listed refer to the cable length measured from the near end master modem to far end slave modem 19 AWG 22AWG 24AWG Baud Rate o 6 19 254 3 10 1310 2 4 6 8 2400 1 2 2 4 12 12 3 4 1 212 14 4800 1 2 2 3 4 1 2 2 3 4 12 2 83 4 9600 1 224 112 2 4 1 212 4 4 19 000 1 2 2 1 2 2 1121214 Table 6 Equalization Settings vs Cab
14. e Covina CA 91722 Tel 626 915 5502 Fax 626 331 9484 E mail support micro aide com
15. e network in accordance with the jumper and switch settings selected in the setup procedure The RS 232 interface will be fully operational The Tst2 and Tst1 LEDs are off when the modem is in Normal Mode 21 LDM User Manual TEST MODE A ANALOG TEST WITH DIGITAL LOOP BACK In Test Mode A the analog signal present at the receive channel is decoded into a digital data signal The receive data signal is then presented to the modem s transmitter section The transmitter outputs the decoded data via the transmit channel In Test Mode A the Tst2 and Tst1 LEDs will be on and off respectively The DTE interface is disabled in this test mode The CD indicator will operate normally The RTS and CTS indicators will illuminate in accordance with the DTE status Neither signal however has an effect on Test Mode A The Rev and Xmt indicators will be off Test Mode A can be used to perform an effective end to end test of a net work segment The modem at the end of the segment under test should be placed in Test Mode A All other modems should be left in Normal Mode Transmitted data will be returned to the source modems receiver where it can be checked against the originally transmitted data TiP Test Mode A requires the same equalization setting as Normal Mode TEST MODE B ANALOG LOOP BACK WITH DTE DATA Test Mode B loops the analog output signal of the transmit channel to the input of the receive channel The data to be transmitted is
16. ected Baud rate The Equalization setting for the near and far end modems must be identical and set in accordance with the recommendations as listed in Table 6 on page 31 Assume a cable length equal to the near end to far end cable length The Equalization setting for a drop point modem must also be set in accor dance with the recommendations as listed in Table 6 on page 31 Assume a cable length equal to the length between the modem 1 master and the drop point modem MuLTI DROP NETWORK Near end Far end LDM 1 Master 7 Slave lt ee Ry Drop point Drop point To Master To Slave DTE DTE To Slave To Slave DTE DTE Figure 4 Typical Multi Drop Network 11 LDM User Manual ACCESSING THE LDM 1 PCB The various LDM 1 settings are controlled by jumpers and switches They are located on the LDM 1 s PCB Only the Equalization SW3 setting can be accessed externally of the standalone modem The other settings require that the cover of the standalone unit be removed or that the plug in PCB be removed from its LDM 16 nest The cover of the standalone unit can be removed by removing the four screws at the side of the unit The plug in PCBs can be removed by first unfastening the hinged front cover of the LDM 16 Remove the PCB retaining bar located at the top front edge of the nest It is secured by two screws The xmt rcv and power connectors should then be unfastened at the rear of
17. ed to the end of the standard har ness WARNING The two position power connector must be inserted on the top two pins of the PCB s six position connector Failure to do so will result in damage to the PCB LDM 16 The LDM 16 nest is a chassis that can be installed in any standard 19 equip ment tack It includes a pair of rack mounting brackets It is 5 75 high and requires four rack increments of vertical space The chassis can be secured at 16 Setup and Installation Installation any convenient location in the rack with four screws Figure 2 on page 7 pro vides front and rear views of the LDM 16 The nest requires access to 120 Vac power It is equipped with a 2 Amp fuse located along the rear panel ATTACHING THE NETWORK LINES The 1 is designed to operate with four wire private line networks Both the transmit and receive channels are polarity sensitive The network s con ductor must always be wired to a corresponding input at the rear panel Network lines are secured to appropriate screw down terminals at the quick disconnect plug The rear panel silk screening clearly labels each connector position The cable that connects the LDM 1 to the network should be lim ited to 100ft in length CONNECTING TO THE DTE The LDM 1 can be used with any DTE that utilizes an RS 232 interface The LDM 1 s operation is asynchronous It uses the Baud rate selected by the DTE The DTE connects to the DB 25 female c
18. est Mode C The Rcv indicator will be on Test Mode C can also be used to test the modem separately from the network and DTE If a DTE 15 connected it should display a sequence of U characters ASCII code 85 TIP Test Mode C requires an equalization setting of 1 i e minimum This completes the chapter on how to operate the LDM 1 The next chapter describes maintenance of the modem 23 LDM User Manual USER NOTES 24 4 MAINTENANCE INTRODUCTION The primary purpose of this chapter is to describe the recommended trouble shooting method to be used with the LDM products It should be referred to if ever a questionable symptom arises during the operation of any LDM device The LDM products are designed to provide users with many years of trouble free operation There are no user serviceable components in any LDM device There are no consumable items or supplies that need to be replaced or replen ished The user may occasionally need to wipe dust away from the external surfaces of a unit This should be done with a clean dry cloth The mechani cal design of the housing and chassis provide the electronic assemblies with a nearly sealed environment Due to the low power requirement of each prod uct ventilation holes are not required The inside of each unit should remain clean indefinitely PCB REMOVAL AND INSERTION The PCB inside the standalone version LDM 1 should never be removed from
19. ff at each of the slave modems 11 Verify the CD LED of each slave modem is on TEST PROCEDURE To test the bit error rate of the network do the following 1 A screen similar to the following should be displayed at the PC after launching the CTSCU exe application 36 TxDOT Applications Test Software C DOCUME 1YRONGAR 1 MYDOCU 1 M AIDEWesigns TxDOT CTSCUT 1 CTSCU EXE n x 1 y in Con cro EE I at ist ics Gu it CCU hannel Configuration Channel Communication Barameters U Communication Parameters unload ALL LCU Comm Parms Best Parameters 2 Execute the Configure gt Channel Configuration command A screen similar to the following will be displayed Channel Using DigiBoards CTRL PGDN for COM Ports lt CTRL ENTER to accept ESC to quit The Channel Number refers to the number of available comm ports in the PC Each of the LCU Numbers must correspond with one and only one LCU thumb wheel setting In the example cited above LCUs 1 3 and 4 are included in the network to be tested 3 Execute the Configure gt Channel Communication Parameters com mand Accept the default parameters as listed below 37 LDM User Manual Data Rate TR D L R8 Timeout Channel lt hbps gt 4 1 9 lt msec gt 668 RRR RR pd CO A CO H NADA SO lt CTRL ENTER to a to quit gt 4 Execute the Configure gt LCU Communication Parameters comm
20. he recommendations as listed in Table 6 on page 31 LDM User Manual POINT TO POINT NETWORK Near end To Master To Slave DTE DTE Figure 3 Typical Point to Point Network MULTI DROP NETWORK The multi drop network involves two or more two pair cable segments Each cable segment includes Xmt and Rev cable pair The ends of the cable are connected to a single modem These modems are also referred to as the near and far end modems The master modem is located at the near end The far end is equipped with a slave modem The intersection of two cable segments forms a drop point A slave modem can be connected to the network at each drop point Figure 4 on page 11 illustrates a typical multi drop network A multi drop network is limited to no more than eight modems The proper setup configuration for a multi drop network is as follows The and Rev Terminations for the near and far end modems must be set to On The Xmt and Rev Terminations for each modem at a drop point must be set to Off 10 Setup and Installation Network Types The RTS signal of the master modem can be permanently asserted Refer to the section entitled Permanently Asserting the RTS on page 15 RTS CTS flow control must be used by each DTE device connected to a slave modem The near to far end cable length must not exceed the recommendations as listed in Table 5 on page 30 for the given cable size and sel
21. hone number of person familiar with the problem Brief description of the problem include any printouts that may have a bearing on the prob lem Method of payment for repair costs out of warranty Send product to the following address MICRO AIDE CORP 685 Arrow Grand Circle Covina CA 91722 Tel 626 915 5502 Fax 626 331 9484 E mail support micro aide com Limited Warranty MICRO AIDE warrants its products to be free from defects in material and workmanship for a period of five 5 years from the date of shipment This warranty is in lieu of any other war ranty expressed or implied In no event shall MICRO AIDE be held liable for incidental or consequential damage resulting from 1 the use of any of its products or 2 any alleged breach of this warranty provision MICRO AIDE s liability shall be limited to repairing replacing at its sole discretion any defective product which is returned in accordance with the MICRO AIDE Material Return Policy Product that has been subjected to abuse misuse alteration accident lightning damage neglect or unauthorized installation or repair shall not be covered by this warranty MICRO AIDE reserves the right to make a final decision as to the existence of any failures and the cause of such failures No warranty is made with respect to custom equipment or products produced to buyer s specifications except as mutually agreed upon in writing MICRO AIDE CORP 685 Arrow Grand Circl
22. igured for hardware handshaking The correct setting involves having the RTS signal track the state of the CD signal A stan dard null modem cable can then be used to interconnect the PSDM and LDM ADU TO LDM 1 The ADU to LDM 1 cable must be assembled in such a way that the LDM 1 15 given a constantly asserted RTS signal The best way to achieve this is to wire pins 4 and 6 together at the LDM 1 end This allows the RTS to be con 34 TxDOT Applications Test Software trolled by the Data Set Ready DSR signal which is always active Crossing of the Receive Data and Transmit Data signals must also be performed This cable is also useful when connecting an LDM 1 to any DTE that does not assert an RTS signal However its application is limited to point to point network segments TEST SOFTWARE CTSCU exe is a DOS application designed to test the operation of LCUs and LDM 1s CTSCU exe can be used to quantify bit error rates over point to point and multi drop networks This section describes in detail how to use the CTSCU exe software to perform a typical communication test WARNING CTSCU exe runs best with 3 X versions of Windows It will not run properly in a Windows XP environment It frequently has performance problems running under Windows 98 REQUIREMENTS To run the CTSCU exe test software the following items are required A Windows 3 X PC with the CTSCU exe software installed One or more LCUs installed with
23. its aluminum case Internal jumpers and switches are accessible once the top cover is removed However access to the user configured settings of the LDM 1 plug in PCB installed within the LDM 16 nest require removal of the 25 LDM User Manual PCB PCB removal should be performed in accordance with the following procedure Refer to Figure 2 on page 7 Power to the nest can be left on while PCBs are being removed and inserted Damage will not occur provided not mal care is exercised CAUTION Electrostatic discharges can cause serious damage to electronic components Normal anti static precautions are recommended when han dling the LDM 1 PCB Disconnect the cables attached to the PCB at the rear of the nest Modems are labeled 1 through 16 Open the hinged front cover If the PCB bracket is still in place remove it from the chassis by unscrewing both ends The PCB bracket can be discarded While depressing the PCB retainer bar rotate the PCB ejector upward and remove the PCB from the chassis Inspect or replace the PCB Change the setup configuration as necessary Install the PCB by aligning its edges with the plastic card guides secured to the top and bottom panels of the nest Push the PCB forward until it clears the retainer bar Attach any cables to their respective PCB connectors Cables are keyed so they can be inserted in only one direction Do not force a cable into a connec tor WARNING The t
24. le Length and Baud Rates DB 25 CONNECTOR WIRING The LDM 1 includes DB 25 female connector It provides the 5 232 inter face to the DTE The connector is wired as illustrated in Figure 7 Carrier Detect Signal Ground Data Set Ready To Permanently Clear to Send Assert RTS Request to Send Receive Data Transmit Data Protective Ground Jumper Pins 4 amp 6 Figure 7 DB 25 Pin Assignments 31 LDM User Manual USER NOTES 32 APPENDIX TXDOT APPLICATIONS INTRODUCTION The LDM 1 is used in a variety of applications by the Texas Department of Transportation It is frequently used in conjunction with the MICRO AIDE Local Control Unit LCU and PSDM and ADU modules manufactured by Coastcom Changeable message signs vehicle detectors and camera pan and tilt systems utilize the LDM 1 to facilitate RS 232 communications NETWORK CONFIGURATIONS The LDM 1 can be used in point to point and multi drop network configura tions Figure 3 on page 10 and Figure 4 on page 11 illustrate the basic differ ences in the two types of networks Several key points concerning each network are described in the following sections POINT TO POINT The point to point configuration is typically used when only a pair of devices need to communicate with each other A single LCU communicating with a PC would be an example Another typical example occurs when a controller needs to communicate with a roadside camera In many cases the co
25. nd digital loop back test modes ncludes transmit channel detector to avoid data transmission collisions Data contention can be resolved at the LDM 1 not at the DTE Allows full duplex operation on four wires Compact size LDM 1 standalone footptint is approximately 5 by 8 and less than 2155 in weight LDM 16 nest can be equipped with 1 to 16 LDM 1 plug in PCBs for appli cations requiring multiple network interfaces at a single location ABOUT THIS MANUAL This document is intended to provide the user with comprehensive easy to read instructions on how to install set up operate and maintain all three LDM products Wherever possible step by step instructions are listed In the event the user has questions about any of the described procedures the user should contact MICRO AIDE for assistance General Description About This Manual MICRO AIDE Corp 685 Arrow Grand Circle Covina CA 91722 Tel 626 915 5502 Fax 626 331 9484 E mail support micro aide com The MICRO AIDE Material Return and Limited Warranty policies can be found on the inside back cover of this manual REVISION LEVEL This User Manual makes specific reference to Revision D of the LDM 1 Additionally this manual is applicable to LDM 1s that have been factory reworked to the Revision D level The revision level can be found near the lower right hand corner of the LDM 1 s printed circuit board PCB TXDOT APPLICATIONS The LDM products are fre
26. ntroller does not support hardware handshaking The LDM 1 will not transmit data until it receives an RTS and then issues a CTS Consequently the RTS signal must be forced to a continu 33 LDM User Manual ously active state Refer to the section entitled Permanently Asserting the RTS on page 15 for details MuLTI DROP Multi drop networks require slave LDM 1s to be connected only to DTEs that support hardware handshaking The MICRO AIDE LCU supports this requirement However the hardware handshaking option must be enabled in the Coastcom PSDM The user should consult Coastcom for information on how a PSDM is enabled for hardwate handshaking Another consideration in multi drop networks concerns the number of LDM 1s that can be placed in one branch of the network No more than seven slave LDM 1s can communicate with a master LDM 1 RS 232 CABLES Each LDM 1 is equipped with a standard DB 25 female connector The con nector is wired in accordance with DCE standards The pin assignments for the connector are illustrated in Figure 7 on page 31 The following list pro vides the user with additional information concerning cable types LCU To LDM 1 The LCU to LDM 1 cable is a simple one to one cable with DB 25 male con nectors at each end A one to one cable can be purchased at any computer supply store It can also be easily assembled using 25 conductor flat ribbon cable and connectors PSDM To LDM 1 The PSDM must first be conf
27. o indication of power Measure 22 26 Vac across power pins of quick disconnect connector DTE data is never transmitted Verify RTS is asserted by DTE Verify DTE LDM cable wiring RTS is asserted but CTS is not asserted Verify one switch in SW2 is closed Verify Tst2 and Tst1 are off Normal Mode Transmit channel may be occupied by another slave modem Transmit data is being sent but Rev Check polarity of transmit and receive LED never illuminates channels connections Table 4 Trouble Shooting Guide 27 LDM User Manual Receive data contains errors Change Equalization settings to better match cable transmission properties Termination settings are incorrect should measure 150 Ohm if On 40K Ohm if Off Test Mode B does not echo sent charac Set Equalization to setting 1 minimum ter U character is not issued in Test Mode C Set Equalization to setting 1 minimum Change Baud rate at DTE to 19 200 Table 4 Trouble Shooting Guide Continued This completes the User Manual for the LDM 1 Two appendices have been provided They include detailed specifications for each of the LDM products and additional information concerning Texas DOT related applications Any comments the reader may have on how to improve this manual are wel comed Comments can be forwarded to the Director of Marketing MICRO AIDE Corporation 28 LDM 1 SPECIFICATIONS Physical Length 8 6 Wid
28. on Network Types NETWORK TYPES The LDM 1 has several options and performance settings that can be config ured by the user Equalization line termination and timer settings are among the various items Before the LDM 1 can be properly set up the type of net work that will be used must be understood and selected The LDM 1 is designed for use in point to point and multi drop networks They are described in the following two sections WARNING The LDM 1 cannot be used in a star network configuration involving spoke lengths that are greater than 100 ft POINT TO POINT The point to point network is the simplest of the two configurations It is characterized by a two pair cable and a single modem at each cable end The cable pairs are referred to as Xmt and for transmit and receive respec tively Figure 3 on page 10 illustrates a typical point to point network The proper LDM 1 setup configuration for a point to point network is as fol lows The Xmt and Rcv Terminations for both modems must be set to On Since only two modems are used the RTS signal of each modem can be manently asserted Refer to the section entitled Permanently Asserting the RTS on page 15 The end to end cable length must not exceed the recommendations as listed in Table 5 on page 30 for the given cable diameter and selected Baud rate The Equalization setting for both modems must be identical and set in accordance with t
29. onnector located at the modem s rear panel The pin assignments for the modem s DB 25 connector are listed in Figure 7 on page 31 It is wired in accordance with DCE stan dards This completes the chapter on how to set up and install the various LDM products The next chapter describes how to operate the modem and how to use its self test features 17 LDM User Manual USER NOTES 18 3 OPERATION INTRODUCTION This chapter describes how to operate the LDM 1 An explanation of each LED indicator and use of the Select Mode pushbutton switch are also pro vided Normal operation and the three test modes are described INDICATORS AND CONTROLS LEDs The front panel of each LDM 1 includes a set of eight multi colored LED indicators The location of each LED and the Select Mode pushbutton switch is depicted in Figure 1 on page 6 The operational mode and signal status of the modem is conveyed via the LEDs A description of each LED is listed in Table 3 on page 20 19 LDM User Manual Table 3 LED Indicators SELECT MODE PUSHBUTTON SWITCH The Select Mode pushbutton switch located at the front panel is used to select Label Name Color Description Pwr Power Red Modem has internal 5 Vdc power CD Carrier Detect Green Data is present on receive channel Flashes if Test Mode C 15 receiving data Tst2 amp Tstl Test 2 amp Test 1 Red Off amp Off Normal Mode On amp
30. quently used with MICRO AIDE s Local Control Unit LCU and other data communications devices throughout the State of Texas They have been approved by the Texas Department of Transportation for use in various highway communications networks Appendix includes information specific to these applications LDM User Manual USER NOTES 2 SETUP AND INSTALLATION INTRODUCTION This chapter describes how to properly unpack set up and install each of the MICRO AIDE LDM products Typical point to point and multi drop net work installations are described Figure 1 on page 6 includes an illustration of the front and rear panels of the LDM 1 standalone modem The LDM 16 nest is illustrated in Figure 2 on page 7 NOTE Unless otherwise stated the term LDM 1 will refer to either version of the modem 1 LDM 1 standalone and LDM 1 plug in The LDM 1 must be properly configured before it can be put into operation As the setup procedure requires that the user have access to the LDM 1 PCB it is advisable that the user complete the setup procedure described herein and then proceed to install the modem LDM User Manual FRONT PANEL MicRO AIDE Eq Select Rev CTS Tst2 Pwr Dist j Xmt RTS CD Limited REAR PANEL as Vac p gt CREED O 232 To DTE Figure 1 LDM 1 Standalone UNPACKING Setup and Installation Unpacking
31. set the AX3 jumper The factory default setting 1s Off RS 232 PROTECTIVE GROUND AX5 Installing the jumper at AX5 will connect the signal ground of the LDM 1 to the protective ground of the DTE device Generally the LDM 1 and DTE can be left isolated from one another by leaving the jumper set to Off The LDM 1 is provided 24 Vac power by a fully isolated transformer The factory default setting is Off RTS To CTS DELAY SW2 The LDM 1 will respond to the DTE s RTS signal by asserting its CTS signal The delay from RTS to CTS is controlled by the SW2 setting The delay can be used to ensure that the transmit channel is available SW2 allows the user to select any of four settings Only one switch must be closed Refer to Table 1 on page 12 Silkscreening on the LDM 1 PCB lists the correspondence between switch position and delay The factory default setting is 8 msec EQUALIZATION SW3 SW3 is a dual position switch that is accessed from the front panel of the modem Refer to Figure 1 on page 6 SW3 allows the user to set the Equaliza tion level required to compensate for the transmission characteristics of the cable being used To provide the broadest performance range possible four 14 Setup and Installation Installation distinct settings are available Table 2 details the correspondence between Equalization settings and switch positions Equalization Switch 3 1 Switch 3 2 Cable Setting Length 1 min
32. th 5 3 Height 1 9 Weight 2207 Environmental Storage Temperature 20 F to 180 F Humidity 0 to 95 non con densing Operating Temperature 4 F to 158 F Humidity 0 to 95 non con densing Mounting Shelf or desktop Construction Housing Fully enclosed anodized alumi num Removable cover allows access to inside Externally accessible LEDs and connectors Electrical Single conformal coated PCB inside housing Power Voltage 24 Vac from MICRO AIDE sup plied wall mount transformer Consumption 2 5W typical Isolation Rcv and Xmt channels are fully isolated from power and DTE TECHNICAL DATA Connectors DB 25 Female Configured as DCE See Figure 7 on page 31 Power Round male connector 6 Conductor Female Pin 1 24 Vac Pin 2 24 Vac Pin 3 Xmt Pin 4 Xmt Pin 5 Rcv Pin 6 Rcv LED Indicators Power Red Carrier Detect Green Test 2 Red Test 1 Red Clear to Send Amber Request to Send Amber Receive Data Red Transmit Data Red Controls External Pushbutton Switch selects operating mode Equalization Switch SW3 dual switch assembly 4 set tings to compensate for cable attenuation Internal DIP Switch SW2 Selects CTS to RTS delay of 8 16 32 or 64msec Jumper AX1 Enables Rcv channel termination of 150 Jumper AX2 Enables Xmt channel termination of 150 Ohm Jumper AX3 Enables Xmt channel busy detector Jumper AX5 Connects DTE signal ground
33. the LDM 16 nest LDM 16 nest a 19 rack mounted chassis that can be equipped with 1 to 16 LDM 1 plug in PCBs The LDM 1 can be thought of as a device for extending RS 232 communica tions over great distances e g thousands of feet It serves as an interface between the customer s Data Terminal Equipment DTE and data communi cations network It is designed to be compatible with four wire private line networks It can be used to facilitate point to point and multi drop network configurations Its unique performance characteristics permit data transmis sion and reception over distances of many miles Additionally the LDM 1 will operate over a wide temperature range LDM User Manual The 1 is easy to install and operate Several self test modes allow the user to verify its performance and network segment integrity Light Emitting Diode LED indicators inform the user of all critical functions KEY FEATURES Listed below are just a few of the features associated with MICRO AIDE s family of LDM products Broad transmission range up to 25 miles point to point at 4800 Baud Data transparent transmission and asynchronous operation Baud rates from 75 to 19 200 Supports multi drop configurations of up to eight LDM 1s Transmission distance and data rate performance are not de rated by adding drop points Standard DB 25 female connector provides simple cabling to any RS 232 device Easy to activate analog a
34. to protective ground 29 APPENDIX Operating Modes Normal Full duplex over 4 wire network Test 2 L Test 1 LED Off Test Mode A Analog test with digital loop back Test 2 LED On Test 1 LED Off Test Mode B Analog loop back with DTE data Test 2 LED Off Test 1 LED On Test Mode C Analog loop back with test data Test 2 LED On Test 1 LED On Data Characteristics Format Fully transparent to all data Baud Rate 75 to 19 200 Network Configurations Point to Point Capacity 2 modems total Refer to Table 6 on page 31 for range specifications Multi Drop Capacity 8 modems total 1 master 1 to 7 slave modems No transmission range de rat ing with additional slave modems Refer to Table 6 on page 31 for range specifications LDM User Manual Line Requirements Type 4 wire Gauge 19 to 24AWG LDM 16 SPECIFICATIONS Physical Length 19 0 Width 10 5 Height 5 4 Weight 2016 with 8 LDM 1 plug in PCBs Receiver Dynamic Range 40dBm to OdBm Termination Impedance Enabled 150 Disabled gt 40KOhm Isolation Fully isolated from power and DTE interface Mounting Mounts into std 19 equipment rack Power Voltage 120Vac 60Hz Consumption 40W with 8 LDM 1 plug in PCBs TRANSMISSION RANGE SPECIFICATIONS The specifications listed in Table 5 apply to both point to point and multi Transmitter Output Level approximately OdBm into 150 4Vp p Source Impedan
35. to section entitled Network Types on page 9 at least two modems must be used The master modem broadcasts to one or more slave modems Each slave modem listens to the data on its receive channel and passes that data to its DTE device Under con trol of its DTE device only one of the slave modems is allowed to respond at a time to the master modem s message The slave modem sends data via its transmit channel The basic transmit and receive methodology employed is summarized by the following rules Only one master modem can be employed per network The master modem broadcasts simultaneously to every slave modem Only one slave modem can respond to the master modem at a time It can only transmit data to the master modem 1 not to another slave modem The slave DTE device via its application controls the response of each slave modem Hardware flow control must be enabled within each DTE device Specifi cally the DTE device must not attempt to send data until its modem has asserted its Clear to Send CTS signal If only two modems are used as is the case in a point to point network the RTS signal of each modem can be permanently asserted Refer to the section entitled Permanently Asserting the RTS on page 15 NorE The LDM 1 master or slave will only transmit data when its Request to Send RTS signal is asserted and the LDM 1 has in response asserted its CTS signal Setup and Installati
36. wo position power connector must be inserted on the top two pins of the PCB s six position connector Failure to do so will result in damage to the PCB Close the front cover JUMPER AND SWITCH LOCATIONS Several jumpers and switches are mounted on the LDM 1 PCB Only SW3 which controls the receive channel Equalization setting is accessible exter 26 Maintenance Trouble Shooting Guide nally The identity and location of each jumper and switch is illustrated in Figure 5 on page 13 TROUBLE SHOOTING GUIDE The following guide will assist the user in resolving problems that may occur with the operation of the LDM 1 It can be especially helpful when attempt ing to operate the modem for the first time Procedures for resolving both local and remote problems are listed Where multiple steps are indicated it is recommended that they be performed in the order listed Removal of any PCB should be performed in accordance with the procedures described earlier in this chapter The three test modes can be very helpful in isolating problems Refer to the previous Chapter 2 entitled Operation for instructions on how to use the test modes If the user is still unable to resolve the problem MICRO AIDE cus tomer service should be contacted The user will be asked to state the prob lem specify related symptoms and indicate any operations or conditions that have a bearing on the problem Symptom or Problem Resolution N
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