Delta AS Series Programming Manual page 952

4. S sets the parity bit. The value 0 indicates None (no parity bit). The value 1 indicates Odd bit checking. The value 2
3
corresponds to Even bit checking. If the value in S3 is not 0, 1 or 2, the instruction uses the default value.
5. S sets the number of end bits. The value 1 (preset) indicates 1 bit. The value 2 indicates 2 bits. If the value in S
4
not 1 or 2, the instruction uses the default value.
6. S sets the communication mode for Modbus communication. The value 0 indicates ASCII (default value). The value
5
of 1 indicates RTU. If the value in S
7. D sets communication port number. The number for COM1 is 1, COM2 is 2, Card1 is 11 and Card2 is 12. If the
setting value is out of the valid range, the instruction does not set the communication port format.
8. You can also directly set the communication port in HWCONFIG in ISPSoft (COM Port settings) or with the special
registers. For more on in HWCONFIG, see the ISPSoft user manual. Refer to Section 6.19.3 for setting the
communication-related SR and SM registers.
9. The communication at the actual communication port changes immediately after you change the setting of the
instruction. If some communication is being carried out at the moment, it is forced to cancel. Additionally, the
corresponding setting value in SM/SR changes accordingly. For details on SM/SR, refer to Section 6.19.3.
10. This instruction does not change any setting for the actual communication port when the communication format
setting is the same as the previous setting.
Example
1. This example uses the PLC COM1 port. Other PLC communication ports are similar in the way you set up the
communication.
2. The contact for the start condition is X0.0.
3. Set the (RS485) communication format of PLC COM1 to 115200, 8, E and 1.
4. Set the (RS485) communication mode of PLC COM1 to ASCII.
5. The following table explains the COMDF operands for the example.
Operand
S
1
S
2
S
3
S
4
is not 0 or 1, the instruction uses the default value.
5
Description
Baud Rate
Number of data bits
Parity bit
Number of end bits
Cha p ter 6 App l ied Ins truc tio ns
115200 bps
8
E
1
is
4
Content value
1152
8
2
1
6 - 6 7 3
6_