|
Pin-out Errata Sheet for 3420
DB-25 Connector Pin Assignments
|
Signal
|
Name
|
Pin #
|
Mode
|
|
GND
|
Ground |
7
|
|
|
TD
|
Transmit Data |
2
|
Output
|
|
RTS
|
Request To Send |
4
|
Output
|
|
DTR
|
Data Terminal Ready |
20
|
Output
|
|
RD
|
Receive Data |
3
|
Input
|
|
CTS
|
Clear To Send |
5
|
Input
|
|
DSR
|
Data Set Ready |
6
|
Input
|
|
DCD
|
Data Carrier Detect |
8
|
Input
|
|
RI
|
Ring Indicator |
22
|
Input
|
Figure 7 - DB-25 Connector Pin Assignments
DB-78 Connector Pin Assignments
|
Port #
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
TD
|
36
|
12
|
27
|
3
|
75
|
51
|
66
|
42
|
|
RD
|
37
|
11
|
28
|
2
|
76
|
50
|
67
|
41
|
|
RTS
|
17
|
31
|
8
|
22
|
56
|
70
|
47
|
61
|
|
CTS
|
16
|
32
|
7
|
23
|
55
|
71
|
46
|
62
|
|
DTR
|
35
|
13
|
26
|
4
|
74
|
52
|
65
|
43
|
|
DSR
|
18
|
30
|
9
|
21
|
57
|
69
|
48
|
60
|
|
DCD
|
38
|
10
|
29
|
1
|
77
|
49
|
68
|
40
|
|
RI
|
15
|
33
|
6
|
24
|
54
|
72
|
45
|
63
|
|
GND
|
34
|
14
|
25
|
5
|
73
|
53
|
64
|
44
|
Figure 8 - DB-78 Connector Pin Assignments
Baud Rate Reference Errata Sheet for the 3421
Appendix E - 3421 Addendum
The COMM+8 can be equipped with a higher speed oscillator and the Startech 16C654 UART. This UART has a significantly larger FIFO (64 bytes as opposed to the 16 of the 16C554). The COMM+8 equipped in this manner can be ordered as the part number 3421.
The 3421 has a 7.3728 MHz oscillator, as opposed to the standard 1.8432 MHz oscillator, that allows data rates up to 460.8 K bps. To use the 3421 with a standard communications package, or to achieve standard data rates (i.e. 1200, 2400, 9600É115.2K) simply select a data rate that is your target data rate divided by 4. For example, if you need a data rate of 9600, you would choose 2400, 9600/4 = 2400.
The following table shows some common data rates and the rates you should choose to match them.
| For this Data Rate |
Choose this Data Rate |
| 1200 bps |
300 bps |
| 2400 bps |
600 bps |
| 4800 bps |
1200 bps |
| 9600 bps |
2400 bps |
| 19.2K bps |
4800 bps |
| 38.4K bps |
9600 bps |
If your communications package allows the use of Baud rate divisors, choose the appropriate divisor from the following table:
| For this Data Rate |
Choose this Divisor |
| 1200 bps |
384 |
| 2400 bps |
192 |
| 4800 bps |
96 |
| 9600 bps |
48 |
| 19.2K bps |
24 |
| 38.4K bps |
12 |
|
57.6K bps
|
8
|
|
115.2K bps
|
4
|
|
230.4K bps
|
2
|
|
460.8K bps
|
1
|
Baud Rates and Divisors for the 'Div1' mode for the 3440 and 3441
The following table shows some common data rates and the rates you should choose to match them if using the adapter in the 'Div1' mode.
| For this Data Rate |
Choose this Data Rate |
| 1200 bps |
300 bps |
| 2400 bps |
600 bps |
| 4800 bps |
1200 bps |
| 9600 bps |
2400 bps |
| 19.2K bps |
4800 bps |
| 38.4K bps |
4800 bps |
|
57.6K bps
|
14.4 bps
|
|
115.2K bps
|
28.8 bps
|
|
230.4K bps
|
57.6 bps
|
|
460.8K bps
|
115.2 bps
|
If your communications package allows the use of Baud rate divisors, choose the appropriate divisor from the following table:
| For this Data Rate |
Choose this Divisor |
| 1200 bps |
384 |
| 2400 bps |
192 |
| 4800 bps |
96 |
| 9600 bps |
48 |
| 19.2K bps |
24 |
| 38.4K bps |
12 |
|
57.6K bps
|
8
|
|
115.2K bps
|
4
|
|
230.4K bps
|
2
|
|
460.8K bps
|
1
|
|
