Switching the SIMATIC Box PC 620 to Active/Passive
When your SIMATIC Box PC 620 is supplied, the COM1 (TTY) serial port is active
(20 mA current loop). When you connect two programming devices using the
COM1 (TTY) serial port, you must deactivate the port on one of these devices. In
the SIMATIC Box PC 620, the switch for this is located on the motherboard.
These jumpers are accessible if you open the battery compartment cover.
Change the jumper settings as shown in Figure 4-10.
Figure 4-10 Jumper Setting TTY Port Active
Changing the Jumper Setting
Proceed as follows to switch the SIMATIC Box PC 620 to passive:
1. Switch off your device.
2. Open the cover of the module.
3. Place the two jumpers in the "open" position (see Fig. 1-10).
4. Close the cover of the module.
SIMATIC Box PC 620 Manual
Setting Up and Operating the SIMATIC Box PC 620
Active TTY port (default setting)
TTY loop transmit separated from power source (passive setting)
TTY loop receive separated from power source (passive setting)