14
3.2
TTL/Relay interface
The TTL / Relay interface is realised as a 25-pin socket. It provides 8 TTL in- puts or
outputs and 8 Relay contacts. The pin assignment of the socket is shown below
.
Table: TTL/Relay interface
Pin Signal
Electrical characteristics
1
TTL 1
input/output
TTL interface:
Capacity of the TTL outputs:
Maximum voltage: 3.3V
Maximum current: 10mA
Relay interface:
Capacity of the relays:
Maximum voltage: 48V
Maximum current: 200mA
2
TTL 2
input/output
3
TTL 3
input/output
4
TTL 4
input/output
5
TTL 5
input/output
6
TTL 6
input/output
7
TTL 7
input/output
8
TTL 8
input/output
9
RELAY 4 (B)
output, NO
10
RELAY 5 (B)
output, NC
11
RELAY 6 (B)
output, NC
12
RELAY 7 (B)
output, NO
13
RELAY 8 (B)
output, NO
14
RELAY 1 (A)
output, NC
15
RELAY 1 (B)
output, NC
16
GND
17
RELAY 2 (A)
output, NC
18
RELAY 2 (B)
output, NC
19
RELAY 3 (A)
output, NO
20
RELAY 3 (B)
output, NO
21
RELAY 4 (A)
output, NO
22
RELAY 5 (A)
output, NC
23
RELAY 6 (A)
output, NC
24
RELAY 7 (A)
output, NO
25
RELAY 8 (A)
output, NO
NO = normally open contact
NC = normally closed contact
1
13
14
25