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AUGUST 1998
PCW22A-R3
PCW22C-R4
Protocol Converter
A/S-2G
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
CUSTOMER
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746
SUPPORT
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
INFORMATION
Web site: www.blackbox.com • E-mail: info@blackbox.com
A/S-2G
PORT A PORT B
TXD RXD RTS CTS DTR DSR CDA CDB TXD RXD RTS
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FCC STATEMENT 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 J of Part 15 of FCC rules, whic
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PROTOCOL CONVERTER A/S-2G INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement) 1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de que el aparato eléctrico sea operado. 2. Las instrucciones de seguridad y operación deberán ser guardadas para referencia futura. 3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas. 4. Todas las instrucciones de operación y uso deben ser seguidas. 5. El
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TABLE OF CONTENTS Table of Contents 1.0 Specifications .......................................................................................................................................5 2.0 Introduction.........................................................................................................................................6 3.0 Installation ........................................................................................................................................
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PROTOCOL CONVERTER A/S-2G 4.2 Synchronous Device to Asynchronous Device........................................................................22 4.2.1 Line Control...............................................................................................................22 4.2.2 Synchronous Input Data Format...............................................................................22 4.2.3 Data Conversion....................................................................................
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CHAPTER 1: Specifications 1.0 Specifications Protocol — Asynchronous: TTY (ASCII) Bisynchronous: 2770, 2780, 3741, and 3780 (EBCDIC) Ports — A: Asynchronous B: Synchronous/bisynchronous Speed — Up to 19.2 Kbps (each port independent) Interface — RS-232 (both ports) Connectors — (2) DB25 (female) Flow Control — Asynchronous: X-ON/X-OFF or DTR/CTS interface lead (in DTE only) Synchronous/bisynchronous: standard BSC handshaking Indicators — Unit Power: PWR Power (LED mounted on Port B side)
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PROTOCOL CONVERTER A/S-2G 2.0 Introduction The Model A/S-2G provides compatibility between an asynchronous, ASCII coded device and a synchronous, EBCDIC coded device. It is desirable, prior to installation, to review the following checklist to ensure the appropriateness of all the devices in the system for the planned application. Synchronous (Bisynchronous) Side - Which Protocol is being used? (2770, 2780, 3741, or 3780) ® If IBM -- is the line to be used a Bisynchronous line? Do you have th
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CHAPTER 3: Installation 3.0 Installation 3.1 UNPACKING AND INSPECTION After unpacking the A/S-2G, inspect it for shipping damage. Should there be any noticeable damage, save the cartons and contact the carrier who delivered the box to place a freight damage claim. To open the A/S-2G, take out the four screws from the bottom. Lift off the cover. With the cover removed, visually inspect for components that may have been loosened in shipment. Shipping damage is rare, but a quick inspection i
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PROTOCOL CONVERTER A/S-2G Block size for the 2770/2780 is normally limited to 160, but block size is 400 if the 2770/2780 has the Multiple Record Transmission. Block size for the 3780 is 512. Switch #4 ON = sends CR LF (Carriage Return, Line Feed) to asynchronous device immediately after each logical end of block character (ETB, or ETX) is received from the synchronous side. OFF = Normal operation Switch #5 ON = Variable-length blocks. This switch causes the records sent by the asynchronous de
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CHAPTER 3: Installation Switch #4 ON = Self-Diagnostics Mode. OFF = Normal Operation. Switch #5, #6—Block Size Specification. 56 OFF OFF 80 Characters OFF ON 128 Characters ON OFF 256 Characters ON ON 512 Characters NOTE For 3741, set SW3, Switch #5: OFF (Fixed length)SW2, Switch #5: OFF, and Switch #6: OFF (128 character block) Switch #7, #8—Asynchronous Parity Specification. 78 OFF OFF Space Parity (always 0) OFF ON Mark Parity (always l) ON OFF Odd Parity ON ON Even Parity NOTE The A/S-2G on
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PROTOCOL CONVERTER A/S-2G NOTE Self-diagnostics will normally display the switches as they are set on the printed circuit board. If the switches were reconfigured (see Section 3.2.4), the switches will be displayed as they are set in the software. 3.2.4 RECONFIGURE SWITCH MODE To enter the Reconfigure Switch Mode, a terminal must be connected to Port A. When you type an ampersand (“&”) and then a pound sign (“#”), the A/S-2G will enter the Self-Diagnostics/Reconfigure Switch menu. Press the
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CHAPTER 3: Installation If SW3, Switch #7 is ON, the A/S-2G will drop DTR when only 32 character spaces remain in the buffer. The A/S-2G will reassert DTR as soon as there are at least 33 character spaces available. For most applications, it is best to configure SW3, Switch #7 ON. If SW3, Switch #7 is OFF, the A/S-2G does not use DTR to control the buffer. Instead, the A/S-2G will issue either an X-ON or X-OFF to control data flow. 3.3.2 CLEAR TO SEND (CTS) SIGNAL OPTIONS The asynchronous po
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PROTOCOL CONVERTER A/S-2G 3.3.5 CARRIER OPTIONS If the carrier detect signal is to be driven by the A/S-2G configuration (DCE), the jumper labeled CAR A ENB must be installed. CAR A ENB is located below U20. Refer to the printed circuit board, Figure 5-2, on page 28. The carrier control jumper, CARR A, in between U18 and U19 on the circuit board (See Figure 5-2 on page 28) should be set as follows: (a) continuous carrier—place the jumper over the ON position. (b) switched carrier equal to th
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CHAPTER 3: Installation there is data to be transmitted. Once the A/S-2G receives CTS from the attached device, it will transmit the data. When the synchronous port (Port B) is configured as DTE, the CTS B jumper must be placed over the CNT position. Place the CTS B jumper over the CNT position when Port B is configured as DCE. 3.4.3 BAUD RATE OPTIONS For externally provided synchronous clocking, the baud rate for the synchronous communication line is determined by the modem or modem elimin
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PROTOCOL CONVERTER A/S-2G 3.4.8 COMMAND PASS-THRU To use the command pass-thru feature, the command must be preceded by &% and terminated by &%. Example: &%-Command-&% Commands consist of character pairs. Each pair must represent a valid Hexidecimal value (i.e. zero through 9 or A through F). Example: To send an escape sequence to an attached ASCII device, such as “ESC A,” the following EBCDIC string must be sent to the A/S-2G: &%lB41&%. 14
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CHAPTER 4: Operation 4.0 Operation By its nature, a protocol converter must operate differently in each direction, since it is communicating with separate devices. Therefore, its operation will be discussed separately for asynchronous to synchronous operation and for synchronous to asynchronous. 4.1 ASYNCHRONOUS DEVICE TO SYNCHRONOUS DEVICE 4.1.1 LINE CONTROL When the A/S-2G is initially connected to an AC power source or reset, the asynchronous device can transmit data. When the synchronous
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PROTOCOL CONVERTER A/S-2G ASCII CHARACTERS NOT TRANSLATED TO EBCDIC CR (Carriage Return) when SW3, Switch #3 is ON, LF (Line Feed), Control characters are not passed. Character Hex Character Hex NUL 00 ACK 06 SOH 01 DLE 10 STX 02 NAK 15 ETX 03 SYN 16 EOT 04 ETB 17 ENQ 05 US 1F Table 4-2. ASCII characters not translated to EBCDIC. In 3741 protocol, each block contains only one record. If SW3, Switch #5 is OFF, the A/S-2G will fill the block with spaces until it reaches 128 characters . If SW3,
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CHAPTER 4: Operation If SW3, Switch #7 is OFF, the A/S-2G will send an X-OFF (ASCII DC3, 13 Hex) to the asynchronous device when RAM reaches a nearly-full state. This prevents data from being lost due to a buffer overrun. When RAM space is available, the A/S-2G will send an X-ON (ASCII DC1, 11 Hex) to resume transmission. Alternatively, if SW3, Switch #7 is ON, the A/S-2G will lower the DTR (Pin 20) when RAM reaches a nearly-full state. When RAM space is available, the A/S-2G will again rais
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PROTOCOL CONVERTER A/S-2G Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device IF 2270 - 2780 AA AA 32 32 32 32 02 (text up to 80 characters), IF, BCC1, BCC2; etc. (last record 26, BCC1, BCC2, FF FF IF 3780 AA AA 32 32 32 32 02 (text up to 80* characters with records separated by 1E, last record in block 1E, 26, BCC1, BCC2, FF FF IF 3741 AA AA 32 32 32 32 02 (up to 128 characters), 26, BCC1, BCC2, FF FF ACK 1 Positive Acknowledgment— Odd AA AA 32
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CHAPTER 4: Operation Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device If A/S-2G buffer is nearly full when asynchronous device is transmitting: X-OFF Holds up transmission while buffer clears DC3 (ASCII 13 Hex) or drop DTR CTS or user-specified lead Send block C Frees up buffer space. ACK 1 (Echo CR LF) X-ON Allow resumption of transmission DC1 (ASCII 11 Hex) or raise DTR Complete block D If data not properly received by synchronous device or sy
