Parallel Centronics Interface; Interface Characteristics - Connector Pin Assignment / Signal Definition - PSI Matrix PP 803 Benutzerhandbuch

A.2 Parallel Centronics
A.2.1. Interface Characteristics - Connector Pin Assignment
/ Signal Definition
Control Signal from the Host. Printer reads data line (Data 1 to
STROBE Data 8) when going low.
Data 1 - 8 Data lines transfer the characters from the host to the printer.
Data 8 = most significant bit.
*)
ACKN
Acknowledge - Negative going pulse from the printer indicates
that the printer has received a character and is ready for the next
data transfer.
BUSY Control signal from the printer. A high level indicates that the
printer is unable to receive any more data.
PE Paper Empty - Control signal from the printer. This signal goes
high when paper runs out, i.e. load upper or lower tractor,
paper jam.
SELECT Control signal from the printer. A high level indicates that the
printer is ON-LINE and ready.
LG Logic Ground
-- not used
LG Logic Ground
CG Chassis Ground
VCC + 5 volt
SG Signal Ground
*)
INIT
Control signal from the host. Does not reset the prin- ter.
FAULT Control signal from the printer. A low level indicates that the
*)
printer has been switched off, or the serial interface is active.
LG Logic Ground
-- not used
SELECT IN Compatible mode (low) 1284 nibble mode (high)
*)
Overlined signal names indicate that the signal is true when the signal level is low.
**)
When the interface buffer is full except for the last character, BUSY will not be reset. BUSY will be
reset when buffer space is available again for least 512 characters in the interface buffer. While the
printer is offline (Stop Mode) BUSY remains active until the printer enters the online state again.
IEEE Std 1284 Nibble mode including Device ID are supported.
The maximum throughput for data transfer is 42,000 characters per second.
Interface
®
Signal Description
Appendix A System Interface Description
**)
Pin No. Return line
Pin No.
1 19
2 - 9 20 - 27
10 28
11 29
12 --
13 --
14 --
15 --
16 --
17 --
18 --
19 - 20 --
31 --
32 --
33 --
34 - 35 --
36 30
Direction
Input
Input
Output
Output
Output
Output
Input
Output
Input
A-9