OP7100
Hardware 39
RX
TX
GND
RTS
CTS
DTR
RX
TX
GND
RTS
CTS
Modem
Side
OP7100
Side
Figure 3-18. Connections Between
Controller and Modem
A program sends data by writing characters into the transmit buffer. If the
serial port is not already transmitting, the write functions will automatically
initiate transmission. Once the last character of the buffer is sent, the
transmit interrupt is turned off. A high-level application can write data one
character at a time or in a string.
CTS/RTS Control
The Z180’s hardware constrains its Port 0 to have the CTS (clear to send)
pulled low by the RS-232 device to which it is talking. The OP7100 does
not support CTS for the Z180’s Port 1.
Modem Communication
Modems and telephone lines facilitate RS-232 communication across great
distances.
The Dynamic C RS-232 library supports communication with a Hayes Smart
Modem or compatible. The CTS, RTS and DTR lines of the modem are not
used. If the modem used is not truly Hayes Smart Modem compatible, tie the
CTS, RTS and DTR lines on the mo-
dem side together. The CTS and RTS
lines on the controller also have to
be tied together. A “NULL-modem”
cable is also required for the TX and
RX lines. A commercial NULL-mo-
dem cable would have its CTS and
RTS lines tied together already on
both sides.
Figure 3-18 shows the wiring for
connections between a modem and
the OP7100.
Summary of Contents for OP7100
Page 1: ...OP7100 Serial Graphic Display User s Manual 019 0065 070831 O ...
Page 10: ...OP7100 x About This Manual ...
Page 16: ...OP7100 16 Overview ...
Page 74: ...OP7100 74 Software ...
Page 82: ...OP7100 82 Graphics Programming ...
Page 88: ...OP7100 88 Installation ...
Page 98: ...OP7100 98 Specifications ...
Page 108: ...OP7100 108 Memory I O Map and Interrupt Vectors ...
Page 112: ...112 Serial Interface Board 2 OP7100 ...
Page 113: ...OP7100 Backup Battery 113 APPENDIX E BACKUP BATTERY ...
Page 116: ...OP7100 116 Backup Battery ...
Page 124: ...OP7100 124 Index ...
Page 126: ...XX0000 Schematics ...