VC3500/VC3700 Troubleshooting Manual
Valco Cincinnati
Page 21
RS232 Board - 151xx375
(Reference Schematic 999xB151-208)
Service Access Points
Connectors
J1, J2
Connection to the CPU board.
J3
Connection for serial port via ribbon cable.
Jumpers
JP1
Hardware/Software Handshaking
Pins 2 & 3 jumpered: Normal configuration. Software handshaking,
CTS
and
RTS
connected.
Pins 1 & 2, 3 & 4 jumpered:
Not used. Hardware handshaking.
JP2 & JP3
Cable Type Selection
Pins 1 & 2 jumpered: Normal configuration.
DB9 to DB9 Null Modem Cable.
Pins 2 & 3 jumpered: DB9 to DB25 and special cables.
Note: JP2 and JP3 must be jumpered in the same manner.
Schematic Description
U1 (PAL20V8) contains all address decoding and miscellaneous logic. The PAL equations
are included on drawing 999XB151-208.
U3 (NS16C552) is an industry standard Dual UART.
U2 (MAX232A) is a single chip RS232 level converter
Crystal Y1 provides clock timing for U3. 1.84 Mhz is divided down within U3 to provide a
Baud rate of 9600 for RS232 communications timing. Other parameters for data transfer are:
Baud Rate
9600
Start Bits
1
Data Bits
8
Stop Bits
1
Summary of Contents for VC3500
Page 1: ...VC3500 User s Manual Software Version 3 X Manual Number MCO35 Manual Release Date July 1999 ...
Page 19: ...Installation VC3500 User s Manual Valco Cincinnati 16 Figure 8 Internal Connections Diagram ...
Page 88: ...VC3700 User s Manual Software Version 3 X Manual Number MCO34 Manual Release Date July 1999 ...
Page 181: ...VC3500 VC3700 Troubleshooting Manual Manual Number MC048 Release Date May 1999 ...
Page 185: ...VC3500 VC3700 Troubleshooting Manual Valco Cincinnati Page 1 System Level Documents ...