Siemens SIMATIC Rack PC 840 V2 Operating Instructions Manual page 132

Detailed descriptions
16.5 BIOS Setup
Internal printer port LPT1
Mode:
Configurable mode
Output Only
Standard Parallel Port -
unidirectional (SSP)
Bi-directional Standard
Parallel Port -
bi-directional
EPP Enhanced Parallel
ECP Extended Capability
Port
"PCI Configuration" submenu
Figure 16-14 PCI Configuration submenu
16-34
Use this setting to set the operating mode of the printer port. Refer to the
table below to ensure that the setting matches the output device you
connected to the printer port.
Features
-Standard setting for 8-bit parallel data transfer to the IEEE1284
specification
-Feedback of the output device is only possible via the control channels
Same as SPP - unidirectional, but:
- Feedback of the output device is also possible via 8-bit data channels.
-High-speed parallel port (data transmission rates between 500 kbps and
2 Mbps are possible)
-Hardware handshake
-different devices can be addressed
Same as EPP, but:
-separate DMA channel
-FIFO buffer
-Data compression
Operating Instructions, Edition 05/2006, A5E00248055-04
SIMATIC Rack PC 840 V2