Technical data

Setting Up and Operating the Computing Unit
3-20
SIMATIC Panel PC 670 Computing Unit Equipment Manual
Edition 12/01
Note
When connecting the computing unit to another programming unit, you must
switch the TTY ports (COM1) in one of the programming units by changing the
jumper setting. When the computing unit is delivered to you, this port is always set
to active.
Switching the computing unit active/passive
The COM 1 (TTY) serial port is set to active (20 mA current loop) when the
computing unit is delivered to you. When you connect to a programming unit
using the COM 1 (TTY) serial port, you must set one of the ports to passive.
The switch for this on the computing unit is located on the motherboard.
These jumpers are accessible by opening the module cover.
Jumper settings
Change the jumper setting as shown in Figure 3-14:
S1-1 S1-2 Function
On On Active TTY port (default setting)
On Off TTY loop transmit isolated from power source (passive setting)
Off On TTY loop receive isolated from power source (passive setting)
On
Off
1
2
Figure 3-14 Jumper Setting, TTY Port Active
Changing the jumper setting
Proceed as follows to set the computing unit to passive:
1. Turn your device off.
2. Open the cover of the module .
3. Place the two jumpers in the “open” position (refer to Figure 3-14).
4. Close the cover of the module .