Epson TM U200D - B/W Dot-matrix Printer Technical Manual page 151

RS-485 interface connector pin assignments and functions
Pin number Signal name
1 FG
2 SD1
3 RD2
4 RD1
5 RD2
7 SG
8 RD1
10 CS 1
11 CS 2
Rev. B
I/O
- Frame ground
O Transmit data
O Transmit data
I Receive data
I Receive data
- Signal ground
O 1) When DTR/DSR is selected, this signal indicates whether the host
computer is BUSY or READY.
DR1 > DR2 indicates that the printer is READY and DR1 < DR2 indicates
that the printer is BUSY. The BUSY condition can be changed depending
on the off-line conditions set by the DIP switches. When the DTR/DSR
control is selected, the printer becomes the BUSY state (DR1 < DR2) under
the following conditions:
Conditions
1. During the period from when the power is
turned on (including resetting using the
interface) to when the printer is ready to
receive data.
2. During the self-test
3. When the cover is open.
4. During paper feeding using the paper feed
button.
5. When the printer stops printing due to a
paper-end.
6. When an error has occurred.
7. When the receive buffer becomes full.
2) When XON/XOFF control is selected:
This signal indicates whether the printer is correctly connected and is
ready to receive data. DR1 > DR2 (READY ) indicates that the printer is
ready to receive data. The signal is always DR1 > DR2 except in the
following cases:
During the period after the power is turned on until the printer is ready to
receive data.
During the self test.
This signal indicates whether the host computer is BUSY or READY.
CS1 > CS2 indicates that the printer is READY and CS1 < CS2 indicates that
the printer is BUSY.
1) When DTR > DSR is selected:
I The signal is checked and data is transmitted only when the host is ready
to receive data (READY) (except for transmitted by GS ENQ, DLE EOT or GS
a).
2) When XON/XOFF control is selected:
Transmits data regardless of the status of this signal.
TM-U200D/U200PD Technical Manual
Function
DIP SW Settings
ON
BUSY
BUSY
-
-
-
-
BUSY
OFF
BUSY
BUSY
BUSY
BUSY
BUSY
BUSY
BUSY
Appendix A-3