Attention: It is recommended to use shielded twisted pair cables for RJ12 cables, with a length not exceeding 100 meters (depending on the PLAN network load). In strong electromagnetic interference environments, cables with metal shielding layers should be used and grounded at one end.

Address setting and communication configuration
The communication between PGD controller and PCO motherboard is based on CAREL's PLAN network or point-to-point protocol. Each PGD controller must have a unique address (1-31, or 0 for point-to-point) and match the 'Associated Controller List' in the PCO motherboard.
3.1 Enter configuration mode
When the handheld device is powered on, press and hold the "1" and "-" keys (i.e. the numeric 1 key and the minus key) on the keyboard for at least 5 seconds, and the display screen will enter the configuration interface (as shown in Fig.3). The cursor will flash in the upper left corner.
Note: Even if the handheld device currently displays "NO LINK" or "1/0 Board xx fault", this operation is still valid.
3.2 Modify the address of the handheld device itself
In the configuration interface:
Press the "1" key once, and the cursor moves to the "Address Value Area" (displayed as nn, default 32).
Select the desired address (1-31, or 0) using the "1" key (the original text may be up and down keys or plus and minus keys, but the document describes using the 1 key loop).
Press the "1" key again to confirm. If the new value is different from the previously saved one, a confirmation interface (Fig.4) will pop up. Press the "1" key to save it to non-volatile memory.
The special meaning of address 0: When the address is set to 0, a point-to-point communication protocol is used between the controller and PCO, rather than a PLAN network. At this point, the "0/board address" area is no longer displayed (as there is no need to select the motherboard). This mode is suitable for one-to-one connections and does not allow multiple handheld devices to share the same PCO.
3.3 Configure dedicated/shared controller (associated with PCO motherboard)
If it is necessary to modify the PCO motherboard controlled by PGD (for example, if there are multiple PCOs in a PLAN network and the controller needs to switch to controlling another one), follow the steps below:
In configuration mode, press the "1" key until the cursor moves to the "x0" area (formerly known as the "0/address" area, as shown in Fig.3 with values such as "0/12").
Press the "1" key to cycle through the PCO motherboard addresses that are currently online on the network. If the network is not working properly or an address does not exist, the area will display a "-" and cannot be modified.
After selecting the PCO address, press the "1" key again, and the screen will switch to the associated settings interface shown in Fig.5.
Use the "1" key to move the cursor between regions, and use the "1" key to change the value of the current region:
Px "area: displays the address of the selected PCO motherboard (e.g." P12 ").
Pin/Shared "area: indicates the type of handheld device. PGD cannot be set as "Sp" (shared printer) and can only be used as a dedicated or shared handheld device (depending on the PCO configuration). Usually, the dedicated mode is chosen.
Move to the "OK?" area, select "YES", and then press the "1" key to confirm. The new configuration will be saved to permanent storage.
Note: If there is no button operation within 30 seconds, the configuration program will automatically exit without saving any changes. This is to prevent accidental modifications.
3.4 PCO Side Association List Settings
In the configuration parameters of the PCO motherboard, there is a "list of dedicated and shared controllers". This list defines which operator addresses can access this PCO. If the PGD controller address is not in the list, communication cannot be established. Therefore, when replacing the old handheld device, it is necessary to ensure that the address of the new PGD is the same as the original handheld device, or modify the list through PCO configuration software (such as CAREL c.design).
Common fault signals and troubleshooting
4.1 “1/0 Board xx fault”
Phenomenon: The display screen shows "1/0 Board xx fault", where xx is the PCO motherboard address.
Reason: The handheld device detected that the associated PCO motherboard (address xx) is offline (such as power failure, communication line disconnection, or motherboard malfunction).
Solution:
Check if the power supply of the corresponding PCO motherboard is normal.
Check if the RJ12 communication cable is securely connected and if the core is broken.
Check the terminal resistance setting of the PCO motherboard (a 120 Ω resistor should be added to both ends of the PLAN network).
If the PCO motherboard has been replaced, the controller address and associated list need to be reconfigured.