Controller
8-14
SIMATIC Rack PC 840 Manual
A5E00104826-03
Termination Enabled
No Termination
No Termination
No Termination
No Termination
terminated by cable
No Termination
Cable with
Terminator
Figure 8-2 Internal and External Termination
8.1.5
Terminating SCSI Devices
Read the device’s documentation to determine how to enable or disable
termination on your particular SCSI device(s). On most internal SCSI devices the
termination setting is controlled by a jumper or a switch. On other internal SCSI
devices you must physically remove or install resistor module(s). On most external
SCSI devices, a terminating plug (a resistor pack embedded in a small plug) is
installed or removed to control termination (see Figure 8-3).
8.1.6
SCSI Cables
You should only use the integrated cable for internal extensions. Another two 16-bit
SCSI devices may be connected up to this cable. The cable is terminated on the
drive-side.
You should only use top quality 68-pin external SCSI cables for external
extensions. The total external cable length may not exceed 2 meters.
Summary of Contents for SIMATIC Box PC 840
Page 8: ...Preface viii SIMATIC Rack PC 840 Manual A5E00104826 03 ...
Page 179: ...B 1 SIMATIC Rack PC 840 Manual A5E00104826 03 Technical Specifications B ...
Page 208: ...Glossary Glossary 22 SIMATIC Rack PC 840 Manual A5E00104826 03 ...
Page 212: ...Index Index 4 SIMATIC Rack PC 840 Manual A5E00104826 03 ...