Star Micronics SP300 Series - Manual (Page 15)

– 11 –
20 mA current loop (option)
Pin no. Signal name
I/O
Function
direction
9 TTY TXDR — Indicates the ground side of the data signal
of 20 mA loop current.
10 TTY TXD OUT Transmitted data of 20 mA current loop.
17 TTY TXDR — Indicates the ground side of the data signal
of 20 mA loop current.
18 TTY RXDR — Indicates the ground side of the data signal
of 20 mA loop current.
19 TTY RXD IN Received data of 20 mA current loop.
23 TTY RXDR — Indicates the ground side of the data signal
at 20 mA loop current.
24 TTY TXD OUT Transmission data of 20 mA current loop.
25 TTY RXD IN Reception data of 20 mA current loop.
RS-422A (option)
Pin no. Signal name
I/O
Function
direction
9 SD (+) OUT Transmitted data
10 SD (–) OUT Transmitted data
17 RD (+) IN Received data
18 RD (–) IN Received data
19 CS (+) IN When the host computer is set to standby
for data transmission, this signal changes to
“SPACE”.
(In this instance, the printer does not check
the signal.)
23 CS (–) IN When the host computer is set to standby
for data transmission, this signal changes to
“SPACE”.
(In this instance, the printer does not check
the signal.)
24 RS (+) OUT Data transmission request signal. When the
printer is ready to receive data, this signal
changes to “SPACE”.
25 RS (–) OUT Data transmission request signal. When the
printer is ready to receive data, this signal
changes to “SPACE”.