BLACK BOX ME800A-R4 Short Haul Modem User Manual

: June 6, 2024
: BLACK BOX

Table of Contents

Specifications
Chapter 2: Introduction
Chapter 3: Installation
Troubleshooting
References
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ME800A-R4 Short Haul Modem
User Manual BLACK BOX ME800A R4 Short Haul Modem

Place a receiving device up to 4 miles from the sending device.
Select DCE or DTE via a DIP switch, so you won’t need special cables.

Customer
Support
Information| Order toll-free in the U.S.: Call 877-877-BBOX (outside the U.S. call 724-746-5500)
FREE technical support 24 hours a day, 7 days a week: Call 877-877-2269 or fax 724-746-0746 • Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018 • Web site: www.blackbox.com • E-mail: info@blackbox.com
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Trademarks Used in this Manual
Black Box and the Double Diamond logo are registered trademarks of BB Technologies, Inc.
UL Is a registered trademark of Underwriters Laboratories.
Any other trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.

FEDERAL COMMUNICATIONS COMMISSION AND
INDUSTRY CANADA RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio-frequency energy, and if not installed and used properly, that is, in strict accordance with the manufacturer’s instructions, may cause interference to radio communication.
It has been tested and found to comply with the limits for a Class A computing device in accordance with the specifications in Subpart B of Part 15 of FCC rules, which are designed to provide reasonable protection against such interference when the equipment is operated in a commercial environment. Operation of this equipment in a residential area is likely to cause interference, in which case the user at his own expense will be required to take whatever measures may be necessary to correct the interference.
Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A limits for radio noise emission from digital apparatus set out in the Radio Interference Regulation of Industry Canada.

Normas Oficiales Mexicanas (NOM)
Electrical Safety Statement
INSTRUCCIONES DE SEGURIDAD

Specifications

Technical Specifications

Approvals	Power supply: UL®, CSA
Data	Flow Control: X-ON/X-OFF;

Data Format: Asynchronous, full-duplex
Interconnect| Two-pair twisted-pair cable
Speed| Up to 115,200 bps at up to 4000 feet (1250 m); Up to 57,600 bps at up to 1 mile;
Up to 9600 bps at up to 4 miles
User Controls| (1) 4-position DIP switch, (1) DCE/DTE slide switch, (1) push- button switch
Interface| EIA RS-232-C;
CCITT V.24, V.28; ISO 2110
Connectors| (1) DB9 female;
(1) 4-position terminal block; (1)121-11;
(1) DC power jack
Indicators| DC This dual Red/Green LED will be green when the Receive Data is low, and red when the Receive Data is high.
RX: This LED can be used to verify proper polarity of the interconnecting lines: it should be green when no data is being transmitted. Red indicates improper line polarity.
Environment| Temperature Tolerance:
Operating: 23 to 86° F (-5 to +30° C);
Storage: 23 to 140° F (-5 to +60° C);
Humidity: 0 to 95% relative humidity, non-condensing
Power| Wallmount power supply: 9 VDC, 500 mA, 115 VAC, UL, CSA
Dimensions| 1.5″H x 5.2’W x 5.2’D (3.8 x 13.2 x 13.2 cm)
Weight| 1.4 lb. (0.6 kg), including power supply

Chapter 2: Introduction

Introduction
These short-haul modems enable you to place a receiving device up to four miles from the sending device. They are switch-selectable for either DCE or DTE applications, eliminating the need for special cables and preventing confusion during installation. The short-haul modems are connected with a twisted-pair cable, using a 4-position terminal block or RJ-11. The units are optically isolated to provide protection from differences in ground potential between the units. The units provide line status (Data Carrier Detect when DCE is selected and Data Terminal Ready when DTE is selected) to indicate that the remote unit is online and ready to communicate. Two dual RED/GREEN indicators on the front panel indicate the status of receive and transmit circuitry as well as the proper polarity of twisted-pair connections. BLACK BOX ME800A R4
Short Haul Modem - figure 1

Table 2-1. Components.

Number	Component	Description
1	Pushbutton	Press this button for Loopback operation.

Chapter 3: Installation

Installation
Before you begin, make sure all equipment, including the converters, are not powered on.

Set the 4-position DIP switch as appropriate for local control signal enable and cable distance.
Set the slide switch for either DCE to connect to a PC or DTE to connect to a modem.
Connect the two short-haul modems with twisted-pair cable, making sure to connect TX+ and TX- on the local unit to RX+ and RX- respectively on the remote unit, and vice versa. You can use either the RJ-11 connector or the 4-wire terminal block.
Once the modems are connected together, connect DB9 cables to equipment and power up the converters.
Next, power up your equipment. For testing purposes, a loopback function has been incorporated into the short-haul modem. Placing the local unit in loopback enables the local unit to be tested without the line, and enables the remote unit to test the line. Placing the remote unit in loopback allows the local unit to test the line. Keep in mind that the unit in loopback sees a cable of zero length, while the other unit sees twice the cable length. This may affect the DIP switch settings and the baud rate at which the test will be successful.

Table 3-1. Four-position
screw terminal connector.

Position	Function
1	TX+
2	TX-
3	RX+
4	RX-

Table 3-2.
RJ-11 connector

Position	Function
1	No connection
2	RX+
3	TX+
4	TX-
5	RX-
6	No connection

Table 3-3. DB9 RS-232 connector

Pin—Signal| DCE Interface Function
(S1-A)| DTE Interface Function
(S1-B)
---|---|---
1 – Data Carrier Detect| Output| Input
2 – Received Data| Output| Input
3 – Transmitted Data| Input| Output
4 – Data Terminal Ready| Input| Output
5 – Signal Ground| Ground| Ground
6 – Data Set Ready| Output (Pulled High)| Input (Pulled High)
7 – Request To Send| Input (connected to pin 8)| Output (connected to pin
8)
8 – Clear To Send| Output (connected to pin
7)| Input (connected to pin 7)
9 – Ring Indicator| Open| Open

DCE— Data Communications Equipment (can connect to a PC)
DTE— Data Terminal Equipment (configured the same as a PC)
NOTES:

When configured as DCE, Data Carrier Detect will be active when the remote unit is driving the line.
When configured as DCE, Data Terminal Ready and Request to Send signals may be used to disable the line driver (see S3). The remote unit will sense this condition and its Data Carrier Detect signal will become negative.
When configured as DTE, Data Terminal Ready will be active when the remote unit is driving the line.
When configured as DTE, Data Carrier Detect and Clear to Send signals may be used to disable the line driver (see S3). The remote unit will sense this condition and its Data Terminal Ready signal will become inactive.

Switches
S1 2-position slide switch (DTE/DCE)
S2 2-position push button switch (loopback); Push button will be in “out” position for loopback.
S3 4-position DIP switch (option switches)

Table 3-4. S1 switch.

Position	Function (See description of RS-232 DB9 connector)
A	Configure as DCE for connection to PC serial port
B	Configure as DTE to simulate PC serial port output

Table 3-5. S2 switch.

Position	Function (See Figure 3-2)
OUT	Normal operation
IN	Loopback

NOTE: When switch S2 is in the loopback position, the output of the local unit is fed back to its input, and the line is looped back so the remote unit can test the line integrity. The remote unit will actually see twice the distance of the line. This should be taken into consideration when determining the maximum baud rate at which the loopback test will be successful.
The local loopback path is compensated for zero-length cable.

BLACK BOX ME800A R4 Short Haul Modem - figure 2

Table 3-6. S3 switch (UP is OFF, DOWN is ON).

Switch Position	1	2	3	4

Hardware Control Enable
(Note 1)
Disabled| OFF| | |
Line Distance
(Note 2)
Short (less than 1000 ft.)| | OFF| OFF|
Reserved| | | | OFF

NOTES:

When hardware control is enabled, both control input signals must be high for transmission to be enabled.
The long and short line distance switches control the current output of the line driver. These switches should be OFF for distances less than 1000 feet and should be ON for distances greater than 1000 feet.

Table 3-7. Indicators.

Indicator	Function
TX	The Green LED is on when the Receive Data is low, and the Red

LED is on when the Receive Data is high.
RX| This LED can be used to verify the proper polarity of the interconnecting lines: it should be green when no data is being transmitted. Red indicates improper line polarity.

Troubleshooting

If the units fail to operate, check the following before calling for technical support.

Are the units powered on? Check to see if the power supplies are plugged into a working AC outlet.
Check to see if the interconnect wire is connected properly, TX+ to RX+, TX- to RX-, at both ends.
Check that switch S3 is set for the proper cable length.
If hardware control is enabled, DTR and RTS must be high to enable data transmission to the remote unit.
Check that the loopback switch S2 is in the Normal position.

Black Box Tech Support: FREE! Live. 24/7. BLACK BOX ME800A R4 Short Haul
Modem - figure 3

Great tech support is just 60 seconds away at 877-877-2269 or blackbox.com.

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© Copyright 2021. Black Box Corporation. All rights reserved. Black Box® and the Double Diamond logo are registered trademarks of BB Technologies, Inc. Any third-party trademarks appearing in this manual are acknowledged to be the property of their respective owners.

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