6 — CANopen COMMUNICATIONS
Curtis Model 3401T – August 2022
pg. 48
PDOs
TPDOs 1–2 and RPDOs 1–4 are preconfigured to transmit and receive data used by the 3401T’s
preset user interfaces. The following topics describe PDO considerations and the preconfigured
PDOs.
Note: TPDO3 and TPDO4 are reserved.
PDO COB-IDs
The following table lists the bits that define a PDO COB-ID:
Bit(s)
Description
31
Indicates whether the PDO is enabled. 0b indicates enabled.
30
Reserved
. Always 0.
29
Indicates whether the COB-ID is 11 or 29 bits. The device supports only
11-bit COB-IDs, so the value is always 0.
11–28
Bits that would be set for 29-bit COB-IDs. For the 3401T, these bits = 0.
7–10
The PDO’s function code. The function codes are listed below:
• RPDO1: 0100b
• RPDO2: 0110b
• RPDO3: 1000b
• RPDO4: 1010b
• TPDO1: 0011b
• TPDO2: 0101b
• TPDO3: 0111b
• TPDO4: 1001b
0–6
The device’s node ID.
For example, if the device’s node ID is 2Eh and RPDO1 is enabled, the RPDO1 COB-ID is 22Eh
PDO Timing
The PDOs are asynchronous and are periodically transmitted and received. The 3401T does not
support synchronous PDOs. The following list describes the PDOs’ event times:
• RPDOs: 60,000ms (1 minute). If the 3401T does not receive data within one minute, the LCD
will display *.* to indicate that data is not being received.
• TPDOs: 40ms
