COMMUNICATION OBJECTS DESCRIPTION
Index
Sub-
index
Name
Type
Access
PDO
Mapping
Value
1800h - 1804h
0
Number of the last sub-index
UNSIGNED8
RO
No
5
1
COB-ID used by the PDO
UNSIGNED32
RW
No
180h / 280h / 380h /
480h / 580h +
Node-ID
2
Transmission Type
UNSIGNED8
RW
No
254
3
Time between transmissions
UNSIGNED16
RW
No
-
4
Compability entry
UNSIGNED8
RW
No
-
5
Event timer
UNSIGNED16
RW
No
0
The sub-index 1 contains the transmit PDO COB-ID. Every time this PDO sends a message to the network, the
identifier of that message will be this COB-ID. The structure of this field is described in table 8.8.
The sub-index 2 indicates the transmission type of this object, which follows the table 8.9 description. Its working is
however different for transmit PDOs:
Value 0:
indicates that the transmission must occur immediately after the reception of a SYNC telegram, but not
periodically.
Values 1 – 240:
the PDO must be transmitted at each detected SYNC telegram (or multiple occurrences of
SYNC, according to the number chosen between 1 and 240).
Value 252:
indicates that the message content must be updated (but not sent) after the reception of a SYNC
telegram. The transmission of the message must be done after the reception of a remote frame (RTR frame).
Value 253:
the PDO must update and send a message as soon as it receives a remote frame.
Value 254:
The object must be transmitted according to the timer programmed in sub-index 5.
Value 255:
the object is transmitted automatically when the value of any of the objects mapped in this PDO is
changed. It works by changing the state (Change of State). This type does also allow that the PDO be transmitted
according to the timer programmed in sub-index 5.
In the sub-index 3 it is possible to program a minimum time (in multiples of 100 µs) that must elapse after the a
telegram has been sent, so that a new one can be sent by this PDO. The value 0 (zero) disables this function.
The sub-index 4 has no function and exists only for compatibility reasons.
The sub-index 5 contains a value to enable a timer for the automatic sending of a PDO. Therefore, whenever a PDO
is configured as the asynchronous type, it is possible to program the value of this timer (in multiples of 1 ms), so that
the PDO is transmitted periodically in the programmed time.
✓
NOTE!
The value of this timer must be programmed according to the used transmission rate. Very short
times (close to the transmission time of the telegram) are able to monopolize the bus, causing
indefinite retransmission of the PDO, and avoiding that other less priority objects transmit their data
The minimum time allowed for this Function in the starter manager SCW100 is 2 ms.
It is important to observe the time between transmissions programmed in the sub-index 3, especially
when the PDO is programmed with the value 255 in the sub-index 2 (Change of State).
Do not forget that PDOs can only be received if the slave is in the operational state.
PDO_MAPPING
Index
Sub-
index
Name
Type
Access
PDO
Mapping
Value
1A00h - 1A04h
0
Number of the last sub-index
UNSIGNED8
RO
No
0
1 - 4
1 up to 4 object mapped in the PDO
UNSIGNED32
RW
No
0
The PDO MAPPING for the transmission works in similar way than for the reception, however in this case the data
SCW100 | 26
