Comtrol C53 User Manual

User Manual

Rocket Port Converter C52/C53

2000137 Rev B

1

Overview

The Comtrol Rocket Port Converters are smart RS-232 to RS-422/485 bi-directional converters. They allow you to convert one RS-232
port to and from either RS-422 or RS-485 ports. You use the converter to control devices with a longer than normal distance between the
host and the device, and to communicate with several devices. Operations like point-to-point and multi-drop are available to meet your
needs.

Rocket Port Converter C53

Features:

• Both the C52 and C53 are RS-232 to RS-422/RS-485 bidirectional converters. The C53 includes isolation protection against high
voltage up to 2000V.

• Comtrol locates the switch settings inside the converter. This protects the system from unintentional changes that would introduce
communication errors without any warning. To make any changes to the operation mode, simply remove the two screws to open the
cover.

• You can power the C52/C53 either from a DC +9V to +30V, 150A power adapter, or the pin 6 and pin 7 on the terminal block.

• LED indicators show the status of transmitting and receiving data, RTS signal, and power.

• Comtrol has added a protect resistor inside the unit to avoid over-current from the remote ground to the converter’s ground.

• Mounting Kit lets you mount the C52/C53 on a wall or any surface.

Overview 2

Specifications

C52/C53 Specification

Current consumption:

Baud rate:

Distance

Note: Baud rate is dependent upon hardware and operating system

configuration.

Optical isolation

C52
C53

Surge protection 25KV ESD for all signals
Dimension 90mm x 60mm x 21mm

Environmental Condition Value

Operating Temperature 0 to 55

Electromagnetic Compliance Status

Emissions:

RFI Emissions: Class A
EN 55022
FCC Part 15: Class A

Immunity:

EN 50082-1

C52 - DC +9V to +30V, 150mA max.
C53 - DC +9V to +30V, 270mA max.

Up to 921.6K bps under 500 feet
(0.15Km)

Up to 4000 feet (1.2 Km) under
115200 bps

No
2000V DC for all signals

o

C

Yes

Yes

Specifications 3

Package Check List

C52 (C53) RS-232 to RS-422/RS-485 bidirectional converter
Power adapter
Cable
Mounting kit
User manual

Installation

1. The RS-232 and RS-422-485 ports are labeled clearly on the surface of the C52 and C53 converters. Prepare the RS-232 cable and
decide the operation mode as well as the 2/4-wire cable in advance. See the RS-232 Cable Wiring and Operations sections.

If you need to change the operation mode, remove the two screws on top of the converter and open the cover. Change the switches to
reflect your desired mode.

The DIP switches set the operation mode (RS-422 or RS-485) and the control mode (by RTS or ADDC) for RS-485 mode.

JP1

AUTO

Switch settings tables of Switch 1 and Switch 2 are as follows:

RS-422 mode Off
RS-485 mode On

485

RTS
422

Switch 1

Switch 2

By RTS Off
Auto Data Direction Control (ADDC) On

2. When you are using the RS-485 in a multi-drop mode, Comtrol includes one jumper per unit to enable the termination resistor. You
only enable the jumper (JP1) at the extreme ends of the chain.

In the RS-422 mode, the RxD always enables a 120 Ohm terminating resistor.

LED Indicators

There are LED indicators for TxD, RxD, RTS, and PWR on top of the unit. The indicators are not on when the unit is not connected with
a signal or power.

• The TxD indicator stands for transmitted data from RS-232 to RS-422 or RS-485. It illuminates when connected and data is
transmitting.

• The RxD indicator stands for received data from RS-422 or RS-485 to RS-232. It illuminates when connected and receiving data.

• The RTS indicator is for the RS-232 RTS signal (Request To Send). It illuminates when it is connected and the RTS signal is on.

• The PWR indicator illuminates when the power is on and not lit when the power is off or not connected.

Installation 4

RS-422/RS-485 Pinouts

The RS-422/RS485 interface with the RJ45 Jack connector or Terminal Block Connector is shown as follows:

RJ-45 Connector Terminal Block Connector

1 2 3 4 5 6 7 8 9 10

1 2 3 4 5 6 7

C52/C53 RS-422

RJ45 Jack Terminal Block

Connector
Pinouts

Signals

Connector
Pinouts

Signals

1 TxD-(A) 1 TxD+(B)
2 RTS-(A) 2 TxD-(A)
3 RTS+(A) 3 RxD+(B)
4 Signal GND 4 RxD-(A)
5 TxD+(B) 5 Signal GND
6 RxD+(B) 6 Power GND
7 Signal GND 7 VCCA(9v)
8 CTS+(B)
9 CTS-(A)
10 RxD-(A)

C52/C53 RS-485

RJ45 Jack Terminal Block
1 Data-(A) 1 Data+(B)
2 nc 2 Data-(A)
3 nc 3 nc
4 Signal GND 4 nc
5 Data+(B) 5 Signal GND
6 nc 6 Power GND
7 Signal GND 7 VCCA(9V)

Note: Pin 6 and Pin 7 of the Terminal Block are for Power GND and Power Input, which is an alternate option for the power adapter. Be

careful that you DO NOT confuse the RS-422/RS-485 (Signal) GND with the power GND.

RS-422/RS-485 Pinouts 5

Operation

Power

Power GND

Power

RxD+(B)

TxD+(B)

TxD-(A)

RxD-(A)

Connector

Connector

The C52/C53 supports four kinds of operations. They are:

• Point-to-point, 4-wire full duplex

• Point-to-point, 2-wire half duplex

• Multidrop, 4-wire full duplex

• Multidrop, 2-wire half duplex

Note: If possible, connect the GND of both sides together to gain better signals. For example, you may need one more GND connection in

addition to the 4-wire or 2-wire connections.

Note: For C53, connect the GND at the terminal block to the earth ground to provide a ground path to prevent electric shock caused by

lightning, no matter whether you use the RJ45 or terminal block RS-422/RS-485.

Basic Communication Wiring

Before placing a converter in an existing network, you should configure it. The following diagrams show a typical layout for both
converters.

RS-422/485

TxD(2)
RxD(3)
RTS(4)
CTS(5)
DSR(6)
GND(7)
DCD(8)
DTR(20)

Host

TxD(2)
RxD(3)
RTS(4)
CTS(5)
DSR(6)
GND(7)
DCD(8)
DTR(20)

Host

RS-422/485

RS-232

RxD(2) TxD+(B))
TxD(3) TxD-(A)
CTS(4) RxD+(B)
RTS(5) RxD-(A)
DTR(6) GND
GND(7)
DCD(8)
DSR(20)

D25 Female

B

RS-232

RxD(2) Data+(B))
TxD(3) Data-(A)
CTS(4) GND
RTS(5)
DTR(6)
GND(7)
DCD(8)
DSR(20)

D25 Female

B

RS-232

A52/53 Converter

A52/53 Converter

RS-485

GND

RS-422 Devices

Data+(B)
Data

-(A)

GND

RS-485 Devices

PC

Operation 6

Reference Section

RS-232 cable wiring examples are listed in the following.

RS-232 Pinouts

The following depicts the RS-232 interface with the RJ45 connector.

C52/C53 RJ45

Connector Pinouts

1 DCD Always On
2 DTR
3 CTS
4 GND
5 RxD
6 TxD
7 GND
8 RTS
9 DSR

10 ------

RS-232 Signals

Note: The DTR and DSR pins have been shorted. This releases the users from

the hardware flow control wiring problems. Therefore, only two types of

Reference Section 7

RS-232 Cable Wiring

Type 1: To connect the RS-232 side of a C52 or C53 to a DTE (Data Terminal Equipment or “your PC”) or DCE (Data Communications

Equipment or “remote device”). Check the precise DTE/DCE pinouts. For an example, see the following DTE/DCE pinout
examples.

C52/C53 to DTE Cable

Pin Pin Signal

DB-25
Male

RJ45

Signal

DCD 1 8 DCD
DTR 2 20 DSR
CTS 3 5 RTS

RxD 5 3 TxD
TxD 6 2 RxD
GND 7 7 GND
RTS 8 4 CTS
DSR 9 6 DTR

C52/C53 to DTE Cable

Signal Pin Pin Signal
DCD 1 1 DCD
DTR 2 4 DSR

RJ45

CTS 3 8 RTS
RxD 5 2 TxD
TxD 6 3 RxD
GND 7 5 GND
RTS 8 7 CTS
DSR 9 6 DTR

DB-9
Male

C52/C53 to DCE Cable

Signal Pin Pin Signal
DCD 1 8 DCD
DTR 2 6 DSR
CTS 3 4 RTS

RJ45 DB-25

RxD 5 2 TxD
TxD 6 3 FxD
GND 7 7 GND
RTS 8 5 CTS
DSR 9 20 DTR

Female

RS-232 Cable Wiring 8

Type 2: To connect the RS-232 side of a C52 or C53 to a DTE (Data Terminal Equipment or “your PC”) with a 3-pin wiring if you don’t

require hardware flow control.

C52/C53 to DTE Cable

Signal Pin Pin Signal
TxD 5 3 RxD
RxD 6 2 TxD

RJ45 DB-25

GND 7 7 GND
RTS 8 5 CTS
CTS 3 4 RTS
DSR 9 20 DTR
DTR 2 6 DSR
DCD 1 8 DCD

Male

C52/C53 to DTE Cable

Signal Pin Pin Signal
TxD 6 2 RxD
RxD 5 3 TxD

RJ45

GND 7 5 GND
RTS 8 8 CTS
CTS 3 7 RTS
DSR 9 4 DTR
DTR 2 6 DSR
DCD 1 1 DCD

DB-9
Male

C52/C53 to DCE Cable

Signal Pin Pin Signal
TxD 6 2 RxD
RxD 5 3 TxD

RJ45 DB-25

GND 7 7 GND
RTS 8 4 CTS
CTS 3 5 RTS
DSR 9 6 DTR
DTR 2 20 DSR
DCD 1 8 DCD

Female

RS-232 Cable Wiring 9

Impedance Matching and Termination Resistors

When an electrical signal travels through two different resistance junctions in a transmission line, the mismatch will sometimes cause
signal reflection. Signal reflection causes signal distortion, which in turn will contribute to communication errors. The solution to this
problem is to establish the same impedance at the RS-485 line ends as in the line itself by terminating them with resistors.

Comtrol manufactures the converter with jumpers to enable and disable termination resistors. To set the jumper, remove the two screws
in the cover and set the jumper to cover both pins.

Troubleshooting

If installation fails or you are trying to resolve a problem, you should try the following before calling the Comtrol technical support line:
For data transmission failure:

• Check that you are using the correct power adapter.

• Check that switches 1 and 2 are properly set.
For data loss or error:
Check that the data rate and data format are the same for both devices

Self Test

This configuration is for C52/C53 self test. Run the terminal emulation program to see if what you received is what you typed.

In the graph, TxD A, TxD B, RxD A, and RxD B could be either from RJ45 or the terminal block.

FCC Notices

Radio Frequency Interference (RFI) (FCC 15.105)

This equipment has been tested and found to comply with the limits for Class A digital devices pursuant to Part 15 of the FCC Rules.
This equipment generates, uses, and can radiate radio frequency energy, and if not installed and used in accordance with the instruction

manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try and correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment and the receiver.

• Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

Labeling Requirements (FCC 15.19)

This equipment complies with Part 15 of FCC Rules. Operation is subject to the following two conditions:

• This device may not cause harmful interference, and

• This device must accept any interference received, including interference that may cause undesired operation.

Modifications (FCC 15.21)

Changes or modifications to this equipment not expressly approved by Comtrol Corporation may void the user’s authority to operate this
equipment.

Serial Cables (FCC 15.27)

This equipment is certified for Class A operation when used with shielded cables.

Impedance Matching and Termination Resistors 10

Contacting Technical Support

Comtrol has a staff of support technicians available to help you. Before you call, please have the following information available:
Comtrol product model number: _______________________
Serial number: _______________________________________
Operating system type and release: _____________________
Computer make: _____________________________________
Computer model: _____________________________________
Processor speed: ______________________________________

Comtrol Corporate Headquarters:

• Web site: http://www.comtrol.com

• E-mail: [e-mail]

• FAX: [phone]

• Tel: [phone]

• FTP site: ftp://ftp.comtrol.com

Comtrol UK Technical Support

• Web site: http://www.comtrol.co.uk

• E-mail: [e-mail]

• FAX: [phone]

• Tel: [phone]

Copyrights and Trademarks

Copyright (c)2000 Comtrol Corporation. All Rights Reserved.
Comtrol Corporation makes no representations or warranties with regard to the contents of this document or to the suitability of the

Comtrol products for any particular purpose. Specifications subject to change without notice. Some features may not be available at the
time of publication. Contact your reseller for current product information.

RocketPort is a registered trademark of Comtrol Corporation.
Other product and company names mentioned herein may be the trademarks and/or registered trademarks of their respective owners.

Contacting Technical Support 11

Notes:

Copyrights and Trademarks 12