11
CHAPTER 2: Introduction
Table 2-3. Pin assignments for sensor input ports
(DB37 female labeled as input).
Port A Bit
P1 Pin
Port B Bit
P1 Pin
0
18, 37
0
10, 29
1
17, 36
1
9, 28
2
16, 35
2
8, 27
3
15, 34
3
7, 26
4
14, 33
4
6, 25
5
13, 32
5
5, 24
6
12, 31
6
4, 23
7
11, 30
7
3, 22
Ground
2, 20, 21
+12 volts
19
+5 volts
1
2.3.3 O
UTPUT
P
ORTS
(R
EED
R
ELAY
)
Reed relays provide very-high-quality, long-life, low-current (10-watt maximum),
dry-contact switch closures. Reed relays are not suited for high-current applications
and can be destroyed by inductive load switching (where a spark occurs across the
contacts internally). The relays are normally open, and they close when energized.
Each relay can be individually energized by writing a “1” to the proper port bit.
Table 2-4 shows the output ports’ pin assignments.
Table 2-4. Output ports (reed relay) pin assignments
(DB37 male labeled as output).
Port C Bit
Relay
P2 Pin
Port D Bit
Relay
P2 Pin
0
K16
2, 20
0
K8
10, 28
1
K15
3, 21
1
K7
11, 29
2
K14
4, 22
2
K6
12, 30
3
K13
5, 23
3
K5
13, 31
4
K12
6, 24
4
K4
14, 32
5
K11
7, 25
5
K3
15, 33
6
K10
8, 26
6
K2
16, 34
7
K9
9, 27
7
K1
17, 35
Ground
18, 36, 37
+5 volts
19
+12 volts
1
