Siemens SIMATIC Panel PC 870 Equipment Manual page 70

Configuring the Computing Unit in BIOS Setup
Printer port internal LPT1
Mode:
Settable Mode
Output Only
Standard parallel port –
unidirectional (SPP)
Bidirectional
Standard parallel port –
bidirectional
EPP
Enhanced parallel port
ECP
Extended capability port
5-14
Use this setting to set the operating mode of the printer interface. Refer
to the table below to ensure that the setting matches the printer
connected to the printer port.
S
Standard setting for the 8 bit parallel transfer
according to IEEE1284 specifications
S
Feedback of the output device is only possible via
the control cables
as for SPP – unidirectional, however:
S
Feedback of the output device is also possible via
the 8 bit data cables
S
Enhanced parallel port (data transfer rate from 500
kbps up to 2 Mbps)
S
Hardware handshake
S
different devices can be addressed
as for EPP, however:
S
own DMA channel
S
FIFO backup
S
Data compression
SIMATIC Panel PC 870 Computing Unit, Equipment Manual
Release 11/02
Features