ComBricks SCOPE Alternate (SALT) Cable Repeater

The ComBricks SCOPE alternative cable repeater (SALT) module makes it possible to use non-standard cable for PROFIBUS communication. Rotary switches adjust the impedance of the cable to match the PROFIBUS Spec. The PROFIBUS telegrams can be inspected with the built in oscilloscope, which is identical to the ComBricks SCOPE repeater module and accessible through the web server.

PROFIBUS networks that have been wired with the wrong cable, for example in situations where it is mandatory to use existing twisted pair cable, are not uncommon. The SALT repeater is an excellent tool to modulate PROFIBUS signals on non-standard media. Moreover, it can also be used to increase the idle-line voltage on segments where idle-line interference causes communication disturbances – which can be helpful even with standard PROFIBUS cable! Large terminal block connectors are provided to allow for different types of specialty cable.

Applications:

• PROFIBUS communication over non-standard cable.
• Idle voltage increaser for EMC sensitive applications – great for standard cable too!
• Impedance tuner for poor segments.
• Installations where large PROFIBUS connectors are required.

The SALT’s repeater channel and the integrated oscilloscope are directly connected with the ProfiTrace OE core in the Head Station. Scope images and busmonitor data are directly available in the web server. The data traffic is constantly monitored for glitches, which are digitally filtered out. It is able to drive 31 devices and has increased signal strength.

2 Rotary switches, one for the middle resistor and one for the 2 pull-up resistors, manipulate the values of the termination network. The combination of both set the impedance and the level of the idle voltage. At the other end of the cable another SALT repeater or the T1-PEPPER has to be placed (to provide matching termination at both ends of the cable).