UBI EasyCoder 501 Service Manual page 136

UBI EasyCoder 501 – Service Manual
18. "UART1:", cont'd.
18.2
RS 232C (V24)
1 /. Warning! Be careful not to enable the
external 5V unintentionally, which may
cause harm to the terminal, PC or other
device connected to this port!
RS 232C (V24) is the most common interface for serial communi-
cation with computers over short distances. The transmission can
only take place between one transmitter and one receiver. The most
simple form of two-way communication only requires a 3-wire
cable. The maximum transmission distance is about 10–15 metres
(33–49 ft.) and the maximum transmission speed is 19,200 baud
(38,400 on optional interface boards).
(external +5V)
- +
P203
3 2 1
P200
IC-200
RS 232C circuit must be fitted on IC-200 (fitted as standard).
Jumper must be fitted on uppermost position of P-202.
RS 422 circuit on IC-207, opto-couplers on IC-205 and IC-206
(optional) and straps on P-204 – P-209 are of no consequence.
The following hardware straps can be fitted:
P-200 DTR-signal:
Pin 1–2 DTR indicates printer turned on.
Pin 2–3 A copy of the flow signal RTS is produced.
P-203 External 5 Volt
Jumper fitted connects +5V to pin 16. Warning! Max 200 mA.
P-203
P-200
(DTR/RTS select)
P202
232
CL
422
(Interface select)
:
1
IC-200
(RS 232C circuit)
P-202
Continued!
136