Specifications

Appendix C: Wiring Diagrams and Pin Assignments 89
SYNC I/O Serial Cable Pin
Assignments
(Macintosh)
The following table shows the pin assignments
for DigiSerial Macintosh.
(Windows)
The following table shows the pin assignments
needed for a SYNC I/O-to-COM cable, to sup-
port SYNC I/O Setup software utility on a Win-
dows computer.
Bi-phase/Tach/GPI/Pilot Port
Interfacing Notes
◆ The six opto-isolators are 6N137 devices. The
four GPI input ports pass through 390 ohm se-
ries resistors to the cathode. The two Bi-
Phase/Tach inputs pass through 634 ohm series
resistors to the cathode.
◆ The two TTL-level GPI outputs are driven by a
74FCT541. Each output passes through a 220
ohm series resistor.
◆ 12 volts is supplied at the connector for the
purpose of driving the opto-isolators in film
tach applications. It is regulated and can supply
up to 100mA.
◆ For Tach, the “rate” input is “BIPHA_I” and
the “direction” input is “BIPHB_I.” The polarity
of “BIPHB_I” is software programmable and de-
faults to “low” for “forward.”
◆ For Bi-phase, the default polarity relationship
between A and B is software programmable. The
default setting for “forward” is “A leads B.” This
means that the rising edge of A (0˚ phase) must
precede the rising edge of B (90˚ phase).
◆ For highest signal quality, use a 25-pin cable
with individually shielded conductors.
DigiSerial for Macintosh
Mini DIN 8-pin Male to Mini
DIN 8-pin Male
12
21
35
44
53
68
77
86
Host Serial for Windows
Mini DIN 8-pin Male to 9-pin
D-Sub Female
27
32
45
53
78
Shell Shell
1, 6, 8 none 1, 4, 6, 9
none