Unimark Sprite, Installation And Operator'S Manual

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Page 11 of 36 REV D1
Sprite Installation and Operator’s Manual
5.0 Host Interface Specifications
5.1 Hardware Interface
The Unit has two RS-232 Asynchronous Serial Communications ports to interface to the Host system. The physical
connection is provided using two DB-25 female pin connectors marked COMM 1 and COMM 2. The ports are
configured as DTE connections and can be used to connect to an associated DTE host using a null modem cable. The
pin-out below provides the basic cabling requirements to connect the Unit to a PC-type host system (table shown assumes
the host system uses a DTE DB-9 connector).
Host (DTE) PC/AT or equivalent Signal Flow
XP (COMM 1 and 2)
Pin #, DB-9 Signal Name Signal Name Pin #, DB-25F
1 CD N/A
2 RxD

TxD 2
3 TxD

RxD 3
4 DTR

DSR 6
5 Signal GND N/A Signal GND 7
6 DSR

DTR 20
7 RTS

CTS 5
8 CTS

RTS 4,11
9 RING

The connection from pin 11 to RTS enables the Unit to function with existing customer cabling. This connection can be
removed if necessary.
The Unit may also have optional hardware interfaces including Ethernet, USB, and Modem. Custom firmware interfaces
can be written for these and the existing serial interface.
5.2 Data Structure
The Unit uses an asynchronous serial data transmission method. Data is sent based on any combination of the following:
Baud Data Length Parity Stop Bit
1200 - 19,200 7, 8 None, Even, Odd 1, 2
6.0 ASCII Control Character List (some characters available with certain firmware versions only)
ACK
- Acknowledge character (06
HEX
). Used to indicate that the message was received correctly.
CR - Carriage Return character (0D
HEX
).
DC1 - XON character (11
HEX
). Used to indicate that the serial port is ready.
DC3 - XOFF character (13
HEX
). Used to indicate that the serial port is NOT ready.
ETX
- End Of Text character (03
HEX
). Used to suffix commands and data to and from the Unit.
LF
- Line Feed character (0A
HEX
).
NAK - Negative Acknowledge character (15
HEX
). Used to indicate that the message was NOT received correctly.
NUL - NULL pad character (00
HEX
).
SOH
- Start Of Header character (01
HEX
). Sometimes used to prefix special commands or messages.
STX
- Start Of Text character (02
HEX
). Used to prefix commands and data to and from the Unit.