Siemens SG-6048-01 User Manual

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Isolated Multi-Drop™ Converter

Operator’s Manual

LOGO

RS485

Por t 1

RS485

Por t 2

RS485

Isolated Multi-Drop™

Por t 3

RS485

Por t 4

Manual No. SG-6048-01

The use of unauthorized parts in the repair of the equipment or tampering by unqualified personnel will result in dangerous conditions which may cause severe personal injury or equipment damage. Follow all safety instructions contained herein.

IMPORTANT

The information contained herein is general in nature and not intended for specific application purposes. It does not relieve the user of responsibility to use sound practices in application, installation, operation, and maintenence of the equipment purchased. Siemens reserves the right to make changes at any time without notice or obligations. Should a conflict arise between the general information contained in this publication and the contents of drawings or supplementary material or both, the latter shall take precedence.

QUALIFIED PERSON

For the purposes of this manual a qualified person is one who is familiar with the installation, construction, or operation of the equipment and the hazards involved.

SUMMARY

These instructions do not purport to cover all details or v ariations in equipment, nor to pr ovi de for every possi ble contingency to be met in connection with installation, operation, or maintenence. Should further information be desired or should particular problems arise which are not covered sufficiently for the purchaser’s purposes, the matter should be referred to the local sales office.

The contents of the instruction manual shall not become part of or modify any prior or existing aggreement, commitment or relationship. The sales contract contains the entire obligation of Siemens Energy & Automation, Inc. The warranty contained in the contract between parties is the sole warranty of Siemens Energy & Automation, Inc. Any statements contained herein do not create new warranties or modify the existing warranty.

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

1.1 Product Summary......................................1

1.2 How to Use This Manual ...........................1

2 Setting Up the Converter.............2

2.1 Overview....................................................2

2.2 RS-485 Communications Ports.................2

2.3 RS-232 Communications Port ..................2

2.4 Power Module ...........................................2

2.5 Configuration Switches .............................2

2.5.1 TX CONTROL Switches................... ...2

2.5.2 Operating in Manual Mode .............. ...3

2.5.3 Operating in Automatic Mode ... ....... ...3

3 Installing the Converter...............4

3.1 Getting Ready............................................4

3.2 Preparing the RS-485 Cable .....................4

3.3 Connecting Directly to a PC......................5

3.4 Connecting with Short-Haul Modems.......6

3.5 Connecting with Dial-Up Modems ............7

4 Testing ACCESS Devices ............8

4.1 Prepare Cable............................................8

4.2 Testing Static Trip III in Type RL

Circuit Breaker...........................................8

4.3 Testing Static Trip III on Desktop...............9

4.4 Testing SAMMS on Desktop .....................9

Contents

5 Troubleshooting .........................11

Appendix A: Block Diagram Appendix B: Mounting Dimensions

ACCESS, Isolated Multi-Drop, Power Monitor PC, SEAbus, SIEServe, Static Trip III , SAMMS and WinPM are trademarks of Siemens Energy & Automation, Inc. Windows is a trademark and Microsoft is a r eg istered trademark of Microsoft Corporation.

Siemens Energy & Automation, Inc.

1 Introduction

1.1 Product Summary

The Siemens Isolated Multi-Drop electronic device that lets you connect your DOS -based PC to the Siemens SEAbus ACCESS can also use the converter to connect other RS-485 devices, such as Multilin 169+ and 269+ relays, to your PC.) The Isolated Multi-Drop converts the RS-232 signal from your PC to an RS-485 signal used in an industrial network such as the ACCESS electrical distribution communications system. With your PC connected to the network in this manner, you can run Siemens WinPM and supervisory software, or Siemens SIEServe and monitoring software for MicrosoftTM WindowsTM, to communicate with every ACCESS device on your system.

The Isolated Multi-Drop converter has four RS-485 ports that can support 32 devices each, for a total of 128 devices on each of your PC’s serial ports. If you are using SIEServe software, you can run one copy of the program for each serial port on your computer.

The Isolated Multi-Drop converter also protects the PC from field-device potentials by providing opto-isolators between the RS-232 and RS-485 interfaces. To isolate the PC further, the converter is equipped with high-energy surge suppression that meets or exceeds ANSI C62.41 (IEEE 587) standards. The converter also incorporates isolated DC/DC converters that provide electrical isolation between the PC and the RS-485 loop.

devices on your power distribution system. (You

communications network for

converter is an

communications

display

1.2 How to Use This Manual

This manual is intended to provide you with all the information you need to install and troubleshoot the Isolated Multi-Drop converter on your ACCESS system. It tells you how to connect your PC and the rest of the ACCESS system directly, and how to connect over longer distances using modems. For help in finding the information you need in this manual, refer to Table 1.1.

Table 1.1 Manual Help

If you need more info about: Refer to:

the features of the converter Section 2 how to install and set up the converter Section 3 how to connect Static Trip units and

SAMMS devices for testing troubleshooting Section 4 mounting dimensions Appendix B

Section 3

The Isolated Multi-Drop converter is designed with features that enable you to set it up and install it easily to meet the specific requirements of your operation.

Siemens Energy & Automation, Inc. 1

2 Setting Up the Converter

2.1 Overview

Before connecting the converter to your system, understand the connectors, LEDs and switches. This section describes each of the following features according to their functions:

• four RS-485 communications ports

• one RS-232 communications port

• power module

• three configuration switches for communications

• manual and automatic operating modes

2.2 RS-485 Communications Ports

The Isolated Multi-Drop converter is equipped with four RS-485 ports located on the converter’s front panel, as illustrated in Figure 2.1

RS-485 receptacles

RS485

2.3 RS-232 Communications Port

The converter is equipped with one RS-232 communications port located on the rear panel, as illustrated in Figure 2.4. This port lets you connect the converter to a PC for desktop operation, or to a short-haul or dial-up modem for remote operation.

2.4 Power Module

The interface of the converter’s power module is located on the rear panel, as illustrated in Figure 2.4. The power module includes an ON/OFF switch, an indicating power (PWR) LED, a 120 VAC power input, and a 15 VDC power output. The 15 VDC output is used to provide power to Static Trip III

trip units and SAMMSTM motor control and protection relays during testing. The filter e d input next to the power switch is for providing line power to the converter. The power switch turns the converter on and off, and the PWR LED illuminates when the converter is turned on.

2.5 Configuration Switches

On the rear panel are the converter’s three configuration switches, collectively labeled “TX CONTROL”. Set these switches before operating the converter. Refer to Figure 2.4 for the location of these switches. The tw o sw itches, l abeled DCD/RTS and MAN/AUTO, and one thumbwheel switch, labeled BAUD are described below. This section describes the uses of each configuration switch in more detail.

Figure 2.1 Connectors on Front Panel Each port allows you to connect as many as 32 field devices

on a single RS-485 communications cable; however, your application software may limit the number of devices your system can accommodate. Each port has Data(+) and Data(-) terminals and a ground terminal for the cable shield.

For diagnostics, each port is equipped with a yellow transmit (Tx) LED and a green receive (Rx) LED, located on top of the device. The Tx LEDs blink during the transmission of data, which occurs on all ports simultaneously; only one Rx LED blinks when data is received. The LEDs are illustrated in Figure 2.2

2.5.1 TX CONTROL Switches

The MAN/AUTO switch places the Isolated Multi-Drop converter in either manual or automatic operating mode, both of which are described below. Your application software determines which mode you should use.

The DCD/RTS switch is set accor ding to the method of data transmission for your configuration. Set the switch to DCD for the Data Carrier Detect (DCD) circuit (pin 8, RS-232 cable) to send a message to the PC when a proper carrier signal is received. Set the switch to RTS for the Request To Send (RTS) circuit (pin 4, RS-232 cable) to send a message to the converter requesting permission to send data on the Tx Data circuit (pin 2, RS-232 cable). Figure 2.3 shows the switches set to DCD and AUTO.

Figure 2.2 Communications LEDs on the Top Panel

Figure 2.3 Tx Control Switches

2 Siemens Energy & Automation, Inc.

Figure 2.4 Rear Panel

2 Setting Up the Converter

The BAUD thumbwheel switch selects the data rate for communications. Set the data rate to be consistent with the data rate for your system’s SEAbus communications network.

Table 2.1 Tx Control Baud Settings

Dial Number Data Rate (bps)

1 1200 2 2400

3 4800

9600

2.5.2 Operating in Manual Mode

Set the converter to manual mode since most Siemens application software uses RTS to enable the Isolated MultiDrop converter’s transmitter. (If your software does not use RTS to enable the transmitter, refer to your user’s manual for more information.) When the Isolated Multi-Dr op conver ter is connected directly to a PC, the MAN/AUTO switch must be set to MAN and the DCD/RTS switch must be set to RTS. When the Isolated Multi-Drop converter is installed at a remote location using short-haul modems, the MAN/AUTO switch must be set to MAN and the DCD/RTS switch must be set to DCD. Short-haul modems typically pass RTS through on the DCD pin at the remote modem.

2.5.3 Operating in Automatic Mode

Set the converter to automatic mode if you use application software that does not support hardware handshaking (that is, DCD/RTS) or that communicates to a remote location via a dial-up modem on a nondedicated telephone line. With the MAN/AUTO switch set to AUTO, the converter’s transmitter is enabled by the data signal transmitted from the computer. To set up the Isolated Multi-Drop converter for Automatic mode, the MAN/AUTO switch is set to AUTO, and the BAUD thumbwheel switch is set to match the data rate on the communications network.

Siemens Energy & Automation, Inc. 3

3 Installing the Converter

3.1 Getting Ready

This section explains how to install the Isolated Multi-Drop converter for your operation. You can install the converter either directly to a PC or remotely within switchgear using short-haul or dial-up modems. This section also tells you how to connect Static Trip III trip units and SAMMS devices to the converter’s power module, enabling you to test these devices in the field.

Before attempting to install the converter, check to see that you have the following parts in addition to the converter:

• a power cord

• a two-terminal connector

• four RS-485, three-terminal connectors Make sure that each device attached to the

Note:

communications network through the converter has a unique address to prevent communications collisions. Device addressing is a process independent of installation. For instructions on how to program the address of a specific device, see the instruction manual for that device or refer to the latest revision of the ACCESS System Installation Guide. (Manual No. SG-6028).

6. Insert the connector into one of the RS-485 ports located on the front panel of the Isolated Multi-Drop converter.

3.2 Preparing the RS-485 Cable

The converter comes with four connectors to connect your system’s RS-485 cable to the converter. Use these connectors to connect as many as four cable runs to the converter’s four RS-485 ports. To install connectors on RS-485 cable, follow these instructions and refer to Figure 3.1:

1. Strip the insulation off the black, white, and shield wires at both ends of the RS-485 communications cable, exposing approximately 0.5inch of metal wire on each.

2. Loosen the three screws in the RS-485 connector.

3. Insert the black wire from both ends of the communications cable into the Data(+) slot on the connector, and tighten the screw to secure the wires.

4. Insert the white wire from both ends of the communications cable into the Data(-) slot on the connector, and tighten the screw to secure the wires.

5. Insert the shield wire from only one end of the communications cable into the center slot on the connector, and tighten the screw to secure the wire.

BLK

WHT

Figure 3.1 Communications Cable Connection

4 Siemens Energy & Automation, Inc.

3.3 Connecting Directly to a PC

To connect the Isolated Multi-Drop converter directly to a PC, you need an RS-232 serial cable of not more than 50 feet in length. Make sure the cable is a DCE-DTE cable, not a null modem cable. The following table lists the minimum set of required signa ls and the pin assi gnments for DB-25 to DB-25 and DB-9 to DB-25 cable connectors:

Table 3.1 RS-232 Pin Assignments

Pin Number

on Connector Signal Name

2TxD 3RxD 4RTS 7GND 8DCD

To connect the converter to a PC, follow these steps while refering to Figure 3.3 below:

3 Installing the Converter

4. Insert the RS-485 connector(s) into the port(s) on the front of the converter. (Refer to section 3.1 for instructions on installing a connector on the RS-485 cable.)

5. Connect the supplied power cord to the 120 VAC connector on the converter, and plug the other end into any 120 VAC grounded power source.

6. Tur n the converter’s power switch on, and verify that the PWR LED is lit. (Refer to Section 5 “Troubleshooting” if the PWR LED is not lit.)

7. Start your software.

1. Connect the plug end of an RS-232 serial cable to the RS-232 port on the Isolated Multi-Drop converter.

2. Connect the socket end of the serial cable to an RS-232 port on your computer.

3. If you are using application software that requires direct DCD/RTS control, set the DCD/RTS switch to RTS and the MAN/AUTO switch to MAN. If you are using application software that does not require the direct DCD/RTS control, set the MAN/AUTO switch to AUTO, and use the BAUD thumbwheel to set the data rate to match that of the application software and the ACCESS devices on the network. (In automatic mode, the converter ignores the setting of the DCD/RTS switch.)

RS-232 Cable

50 Ft. Maximum

with

Supervisory

Software

SHLD

Port 4

Port 3

Port 2

Port 1

SHLD

Isolated Multi-Drop

Converter

22 AWG Shielded

Twisted-Pair Cable

4000 Ft. Maximum

RS-485

Bus

To Other

RS-485 Devices

Device

Up to 32 devices

Figure 3.2 Connecting the Converter Directly to a PC

Siemens Energy & Automation, Inc. 5

3 Installing the Converter

3.4 Connecting with Short-Haul Modems

If the distance between your PC and Isolated Multi-Drop converter is greater than 50 feet but less than 3.5 miles, you can connect them using short-haul modems and regular telephone cable. To install the Isolated Multi-Drop converter using short-haul modems, you need these items:

• two short-haul modems

• telephone cable that does not exceed 3.5 miles in

length

• one Isolated Multi-Drop converter mounting kit (if you

want to mount the converter in a switchgear panel)

• one or two RS-232 serial cables

for either side of the modem connection

For the RS-232 cables, use DCE-DTE cable with the pin assignments given in Table 3.1. For mounting to a switchgear panel, mount the converter before wirin g. (Refer to Appendix B for mounting dimensions.) Then follow these steps, referring to Figure 3.3.

1. Connect short-haul modems to the RS-232 port on the

converter and to the RS-232 port on the PC. Plug them directly into the ports or use the RS-232 serial cables. (If you need help in connecting the modems and setting their switches, refer to the modem’s manual.)

3. Insert the RS-485 connector(s) into the port(s) on the front of the converter. (Refer to section 3.1 for instructions on installing a connector on the RS-485 cable.)

4. Connect the supplied power cord to the 120 VAC connection on the converter, and plug the other end into any 120 VAC gro unded powe r sour ce .

5. Tur n the converter’s power switch on, and verify that the PWR LED is lit. (Refer to Section 5 “Troubleshooting” if the PWR LED is not lit.)

6. Start your software.

2. If you’re using application software that requires direct DCD/RTS control, set the DCD/RTS switch to DCD and the MAN/AUTO switch to MAN. If you are using application software that does not require direct DCD/ RTS control, set the MAN/AUTO switch to AUTO, and use the BAUD thumbwheel to set the data rate to match that of the application software and the ACCESS devices on the network. (In Automatic mode, the converter ignores the setting of the DCD/RTS switch.)

Two Twisted-Pair Cables

3.5 Miles Maximum

RS-232 Cable

with

Supervisory

Software

50 Ft. Maximum

Short-

Haul

Modem

Short-

Haul

Modem

RS-232 Cable

50 Ft. Maximum

SHLD

Port 4

SHLD

Port 3

SHLD

Port 2

SHLD

Port 1

Isolated Multi-Drop

Converter

22 AWG Shielded

Twisted-Pair Cable

4000 Ft. Maximum

RS-485

Bus

To Other

RS-485 Devices

Device

Up to 32 devices

Figure 3.3 Connecting With Short-Haul Modems

6 Siemens Energy & Automation, Inc.

3.5 Connecting with Dial-Up Modems

If the distance between your PC and Isolated Multi-Drop converter is greater than 3.5 miles, you can connect them using dial-up modems. To install the Isolated Multi-Drop converter using dial-up modems, you need these items:

• two dial-up modems

• one RS-232 serial cable no more than 50 feet in length

(unless your PC’s modem is directly installed in the computer)

• one null modem cable no more than 50 feet in length

• a telephone line for each modem

• one Isolated Multi-Drop converter mounting kit (if you

want to mount the converter to the switchgear panel)

If you are mounting the Isolated Multi-Drop converter to a switchgear panel, do that first. (Refer to Appendix B for mounting dimensions.) Follow these steps, while referring to Figure 3.4.

1. Connect one dial-up modem to your PC; use RS-232

serial cable unless your modem is installed directly in the computer. (If you need help in connecting the modems and setting their switches, refer to the modem’s manual.)

2. Using a null modem cable, connect one dial-up modem

to the RS-232 port on the converter according to Figure 3.5.

3. Set the MAN/AUTO switch to AUTO, and use the

BAUD thumbwheel to set the data rate to match that of the application software and the ACCESS devices on the network. (In Automatic mode, the converter ignores the setting of the DCD/RTS switch.)

3 Installing the Converter

1 2 3 4 5 6 7 8

Modem

Figure 3.5 Pin Assignments for Null Modem Cable

4. Insert the RS-485 connector(s) into the port(s) on the front of the converter. (Refer to section 3.1 for instructions on installing the connector on the RS-485 cable.)

5. Plug one end of the converter’s power cord into the 120 VAC connection on the converter, and plug the other end into any 120 VAC grounded power source.

6. Tur n the converter’s power switch on, and verify that the PWR LED is lit. (Refer to Section 5 “Troubleshooting” if the PWR LED is not lit.)

7. Start your software.

Isolated

Multi-Drop

Converter

1 2 3

Pins 2 and 3

Transposed

4 5 6 7 8

Not required

with converter

Device

Up to 32 devices

with

Supervisory

Software

RS-232 Cable

50 Ft. Maximum

Modem Modem

IMPORTANT

Use a

null modem

between the Isolated Multi-Drop Converter

and the modem.

Null Modem Cable

50 Ft. Maximum

cable

SHLD

Port 4

SHLD

Port 3

SHLD

Port 2

SHLD

Port 1

Isolated Multi-Drop

Converter

22 AWG Shielded

Twisted-Pair Cable

4000 Ft. Maximum

RS-485

Bus

To Other

RS-485

Devices

Figure 3.4 Connecting the Converter with Dial-Up Modems

Siemens Energy & Automation, Inc. 7

4 Testing ACCESS Devices

You can use the Isolated Multi-Drop converter’s 15 VDC power output to provide DC power for testing Static Trip III trip units or SAMMS devices. According to the steps in this section, first prepare a cable for connecting the devices to the converter. Then follow the appropriate procedure for the specific device(s) you want to connect to the converter.

4.2 Testing Static Trip III in Type RL Circuit Breaker

If you are testing a Static Trip III trip unit in a Type RL circuit breaker, follow these steps to connect the trip unit to the converter for 15 VDC power, while referring to Figure 4.2:

4.1 Prepare Cable

To prepare the cable, follow these steps while referring to Figure 4.1.

1. Select a two-conductor cable of sufficient length to reach between the converter and the device(s) you want to connect.

2. Strip the insulation from both wires at both ends of the cable, exposing approximately 0.5 inch of metal wir e on each.

3. Loosen the screws in the two-terminal connector that comes with the converter. Insert one wire into each slot on the connector, making sure to take note of polarity.

1. Plug the connector of the two-conductor cable into the 15 VDC output port.

2. Making sure to observe the polarity of the cable, connect the other end to terminals 2 and 3 on the terminal block for cubicle disconnect. (This terminal block is located on the inside left panel of the Type RL circuit breaker compar t ment.)

3. Connect an RS-485 cable between the terminal block in the circuit breaker and the converter. (You may need to prepare a length of communications cable as described in section 3.1 above.) Plug the cable’s threeterminal connector into an RS-485 port on the front of the converter. Connect the black wire from the other end of the cable to Data(+) (terminal 4) on the terminal block, and connect the white wire to Data(-) (terminal 5) on the terminal block.

4. Plug one end of the converter’s power cord into the 120 VAC connection on the converter, and plug the other end into any 120 VAC grounded power source.

5. Turn the power switch on.

6. Using testing software supplied by Siemens, verify that the attached trip unit communicates properly.

Isolated Multi-Drop

rear panel

BLK

WHT

Figure 4.1 Two-Terminal Connector for Test Connection Use this cable to connect devices to the converter

according to the procedur es in the r emainder of this section.

15VDC

OUT

RS485

RS485 RS485 RS485

RS485

Two-wire cable

RS-485 cable

front panel

BLK

WHT

Terminal block for cubicle disconnect

on inside-left panel of

Type RL circuit breaker

+/- 15 VDC

Data (+) Data (-)

compartment

Figure 4.2 Test Connection for Static Trip III

in Type RL Circuit Breaker

8 Siemens Energy & Automation, Inc.

4 Testing ACCESS Devices

4.3 Testing Static Trip III on Desktop

If you are testing a Static Trip III trip unit on a desktop, follow these steps to connect the trip unit to the converter for 15 VDC power, while referring to Figure 4.3:

1. Plug the connector of the two-conductor cable into the 15 VDC output port.

2. Making sure to observe the polarity of the cable, connect the other end to terminals 2 and 3 on the 10-pin connector supplied with the Static Trip III.

3. Connect an RS-485 cable between the 10-pin connector and the converter. (Y ou may need to pr epare a length of RS-485 cable as described in section 3.1 above.) Plug the cable’s three-terminal connector into an RS-485 port on the front of the converter. Connect the black wire from the other end of the cable to Data(+) (terminal 4) on the 10-pin connector, and connect the white wire to Data(-) (terminal 5) on the 10-pin connector.

4. Plug the 10-pin connector into the 10-pin connector port located on the back panel of the Static Trip III.

5. Plug one end of the converter’s power cord into the 120 VAC connection on the converter, and plug the other end into any 120 VAC grounded power source.

6. Turn the power switch on.

7. Using testing software supplied by Siemens, verify that the attached trip unit communicates properly.

Isolated Multi-Drop

rear panel

15VDC

OUT

RS485

RS485 RS485 RS485

RS485

Two-wire cable

RS-485 cable

front panel

1 2 3

BLK

WHT

5 6 7

8 9

10-pin connector on Static Trip III

+/- 15VDC

Data (+) Data (-)

4.4 Testing SAMMS on Desktop

If you are testing a SAMMS device on a desktop, follow these steps to connect the device to the converter, while referring to Figure 4.4 on the next page and to the SAMMSLV User’s Manual (Manual No. MC-3298) or SAMMS-MV User’s Manual (Manual No. MVC-9108):

1. Prepare 2 two-conductor cables by connecting them to one two-terminal connector, as described at the beginning of this section and illustrated in Figure 4.4.

2. Plug the connector of the two-conductor cables into the 15 VDC output port.

3. Making sure to observe the polarity, connect the other end of one of the two-conductor cables to terminals 5 and 6 of the terminal block on top of the SAMMS.

4. Again making sure to observe polarity, connect the other end of the second two-conductor cable to the PWR (+) and PWR (-) terminals on the five-terminal connector supplied with the SAMMS Communication Module CM-1.

5. Connect an RS-485 cable between the SAMMS fiveterminal connector and the converter. (You may need to prepare a length of RS-485 cable; see section 3.1.)

6. Plug the cable’s three-terminal connector into an RS-485 port on the front of the converter. Connect the black wire from the other end of the cable to the (+) terminal on the five-terminal connector, and connect the white wire to the (-) terminal on the connector.

7. Plug the five-terminal connector into the SAMMS Communication Module CM-1.

8. Connect the CM-1 to the SAMMS device using the supplied ribbon cable as illustrated in Figures 12 and

13.

9. Plug one end of the converter’s power cord into the 120 VAC connection on the converter, and plug the other end into any 120 VAC grounded power source.

10. Turn the power switch on.

11. Using testing software supplied by Siemens, verify t hat the attached SAMMS device communicates properly.

Figure 4.3 Connecting a Static Trip III for Desktop Testing

Siemens Energy & Automation, Inc. 9

4 Testing ACCESS Devices

Isolated Multi-Drop

rear panel

15VDC

OUT

RS485

Two-wire cable

RS485 RS485 RS485

RS485

front panel

RS-485 cable

Figure 4.4 Connecting SAMMS Device for Testing

Pins 5 and 6

2345678910

131415

11 12

SAMMS device

Ribbon cable

CM-1

10 Siemens Energy & Automation, Inc.

5 Troubleshooting

If you experience communications errors and suspect the Isolated Multi-Drop converter is at fault, perform the actions listed below . Befor e performing these tests:

1. Verify that your application software is properly set up.

2. Verify that the cables between the components are connected correctly according to the installation instructions.

If transmission through the Isolated Multi-Drop converter fails (one or more of the Tx LEDs fails to blink), perform the following checks in the order given:

1. If some (but not all four) of the Tx LEDs blink simultaneously, the Isolated Multi-Drop converter is faulty and should be replaced.

2. If none of the Tx LEDs flash, perform the following steps in order:

a. Check the power connection and verify that the

PWR LED is lit.

5 Troubleshooting

b. Verify that the Tx Control switches ar e set

according to the specifications of your application software.

c. Verify that the PC’s serial port is working properly. If

it is, try replacing the cable to the converter.

If data errors occur or if there is no response from the field devices (Rx LED fails to flash), perform the following checks in the order given:

1. If correct data is transmitted from a field device but communication errors occur or no Rx LED flashes, check the following:

a. Verify that the field device is receiving power. b. Verify that the cable from the converter to the field

device is correct.

c. Verify that the device’s communications address

matches the address assigned by the software for that device.

d. Verify that the device’s data rate matches that of

the software.

2. Verify proper operation of the attached field device’s RS-485 communication interface. For more detailed troubleshooting information on field devices, refer to troubleshooting guidelines in Installing the ACCESS System (Manual No. SG-6028).

3. Verify that the Data(+) and Data(-) port of each device is connected to the corresponding ports of the converter.

Siemens Energy & Automation, Inc. 11

5 Troubleshooting

NOTES:

12 Siemens Energy & Automation, Inc.

Appendix A: Block Diagram

The illustration below is a block diagram showing how the Isolated Multi-Drop converter operates. The diagram identifies the internal components that make up the converter.

Galvanically Isolated RS-485 Logic

Appendices

RS-232 Connector

25-pin D Connector

RXD

TXD

RTS

DCD

Signal Ground

RS-232 Transceiver

Baud Switch

RTS/DCD

RTS

DCD

Enable

Logic

AUTO/MAN

MAN

AUTO

Tx Enable

Opto-isolators for each data channel

RS-485 Transceiver (4)

Earth Ground

SHIELD

RS-485 Port 1

RS-485 Port 2

RS-485 Port 3

RS-485 Port 4

120 VAC/ 125 VDC

Source

Power Supply

Earth Ground

15V

Isolated Supply

External 15V DC output

Figure A.1. Block Diagr am

Siemens Energy & Automation, Inc. 13

Appendices

14 Siemens Energy & Automation, Inc

Appendix B: Mounting Dimensions

The illustration below shows the mounting dimensions for the Isolated Multi-Drop converter. Use these dimensions to muont the converter to a switchgear panel or to some other location. For more information on installation, refer to section 3, Installing the Converter.

Appendices

8.4

Figure B.1. Mounting Dimensions

Siemens Energy & Automation, Inc. 15

Appendices

16 Siemens Energy & Automation, Inc

Siemens Energy & Automation, Inc.

Switchgear and Motor Control Business P.O. Box 29503 Raleigh, NC 27626-0503

Manual No. SG-6048-01 (Replaces -00) 1M 0595FP Printed in U.S.A.

SIEMENS is a registered trademark of Siemens AG

Siemens SG-6048-01 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1 Introduction

1.1 Product Summary

1.2 How to Use This Manual

2 Setting Up the Converter

2.1 Overview

• power module

2.2 RS-485 Communications Ports

2.3 RS-232 Communications Port

2.5 Configuration Switches

3 Installing the Converter

3.1 Getting Ready

3.2 Preparing the RS-485 Cable

3.3 Connecting Directly to a PC

Figure 3.3 Connecting With Short-Haul Modems

3.5 Connecting with Dial-Up Modems

4 Testing ACCESS Devices

4.2 Testing Static Trip III in Type RL Circuit Breaker

4.1 Prepare Cable

4.3 Testing Static Trip III on Desktop

4.4 Testing SAMMS on Desktop

5 Troubleshooting

Appendix A: Block Diagram

Appendix B: Mounting Dimensions