Bypassing SI_SCOPE's Internal Cable Check
Sometimes it is useful to configure SI_SCOPE not to perform its own internal cable check. This can be helpful in situations where you are working on a three wire system or if you are using SI_SCOPE to debug an embedded device using TTL signal levels. In these situations you may need to construct your own cabling that is tailored to your RS232/RS485 environment. To do this you will need to edit the "CABLE-SETTINGS" section of the file SI_SCOPE.INI that was installed to your Windows directory. Modify the CABLE_TYPE parameter to be either PASSIVE or ACTIVE. The setting you choose depends on how you have your system wired as explained below.
| CABLE TYPE | DESCRIPTION |
| PASSIVE | When set to PASSIVE the program will operate under the assumption that the RX pin on port 1 is connected to the TX line of the link being debugged. The RX pin on port 2 is assumed to be connected to the RX line of the link being debugged. Therefore SI_SCOPE will display any received serial data on port one as data from the DTE device and data on port 2 as data from the DCE device. |
| ACTIVE | If this value is set to ACTIVE the SI_SCOPE will operate in active mode. It will assume that the DTE source is connected to port 1 with NULL MODEM cable and the DCE source is connected to port 2. Therefore SI_SCOPE will display any received serial data on port one as data from the DTE device and data on port 2 as data from the DCE device. |
Note: If you are not using your PC's DCD, DSR, CTS, or RI pins they should be connected to ground.