Casio UP-250 Technical Manual page 146

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 CS1
11 CS2
NOTES:
Receive buffer full state differs depending on the printer models. Refer to the specifications
for the printers.
The data received is ignored when the space in the receive buffer is 0 byte.s
I/O
— Frame ground
O Transmit data
O Transmit data
I Receive data
I Receive data
— Signal ground
1) When DTR/DSR is selected, this signal indicates whether the host
O
computer is BUSY or READY. DR1 > DR2 indicates the printer is
READY and DR1 < DR2 indicates 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 goes into the
BUSY state (DR1 < DR2) under the following conditions:
Conditions
1. During the period from when 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
ready to receive data. DR1 > DR2 (READY) indicates 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 the printer is READY and CS1 < CS2 indicates 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 transmissions by GS ENQ,
DLE EOT, or GS a. .
2) When XON/XOFF control is selected:
Transmits data regardless of the status of this signal.
Function
— 137 —
DIP SW Settings
ON OFF
BUSY BUSY
BUSY BUSY
— BUSY
— BUSY
— BUSY
— BUSY
BUSY BUSY