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SIMATIC PC RI25/45, Technical Description
C79000-G7076-C808-01
The parallel port offers three transmission modes: SPP, EPP, and ECP. The
SPP mode (Standard Parallel Port mode) is the standard mode which is
usually used to trigger or address a printer. Both EPP (Enhanced Parallel
Port) and ECP (Extended Capabilities Port) are transmission modes which
permit data transfer rates of 2 up to 2.4 Mbytes/s. Such rates require I/O
devices which support these new modes.
Both modes are used, for example, for converting a parallel port to an SCSI
or to an IDE port. Each mode has an individual pinout.
1
13
14
25
Figure 2-8 LPT1 parallel port
Pin No.
Description
Input/Output
1
/Strobe
Output (open collector)
2
Data - Bit 0
Output (TTL level)
3
Data - Bit 1
Output (TTL level)
4
Data - Bit 2
Output (TTL level)
5
Data - Bit 3
Output (TTL level)
6
Data - Bit 4
Output (TTL level)
7
Data - Bit 5
Output (TTL level)
8
Data - Bit 6
Output (TTL level)
9
Data - Bit 7
Output (TTL level)
10
/ACK (Acknowledge)
Input (4.7 k
W
pull up)
11
BUSY
Input (4.7 k
W
pull up)
12
P.E.
Input (4.7 k
W
pull up)
13
SELECT
Input (4.7 k
W
pull up)
14
/AUTO FD
Output (open collector)
15
/ERROR
Input (4.7 k
W
pull up)
16
/INIT
Output (open collector)
17
SELECT IN
Output (open collector)
18
:
25
GND
–
LPT1 Printer Port
Signal
Description
SPP Mode
Motherboard