AH500 Programming Manual D 2 +1: Condition of ending the receiving of data D 2 and D 2 +1 are described below. 9. If the value in D2 is in the range of 1 to 5, the maximum number of characters which can be received is 1000. After 1000 characterse are received, the execution of the instruction will stop. 10. The relation among communication port, related spcial auxiliary relays, and a related special data register are described below. 6-424 D 2 Mode of receiving data Setting value in D +1 2 Remark 0 Not receiving communication data Unused After the sending of data is complete, a completion flage will be set to ON.
1 When the time which passes before the next piece of data is received exceeds the time set in D +1, the receiving of 2 data is complete. The setting value in D +1 2 is time. The unit of measurement for time is 1 millisecond. The setting value in D +1 is in the 2 range of 2 to 3000. If the time that users set is greater than 3000 milliseconds, the value in D +1 will be 3000. If the 2 time that users set is less than 2 milliseconds, the value in D +1 will be 2. 2 2 The data received ends with a specific character. The setting value in D +1 2 is a specific character. If a specific character is 16#0A, the value in D +1 2 will be 16#000A.
3 The data received ends with two consecutive specific characters. The setting value in D +1 2 is two specific characters. If two specific characters are 16#0D and 16#0A, the value in D +1 will be 2 16#0D0A. 4 The data received starts with a specific character. When the time which passes before the next piece of data is received exceeds the time set in D +1, the receiving of 2 data is complete. A specific character is stored in the high byte in D +1, and time is stored 2 in the low byte in D +1. 2 (The time set in the low byte in D +1 is in the 2 range of 2 milliseconds to 255 millseconds.) If a start character is 16#3A, and time is 15 milliseconds, the value in D +1 will be 16#3A0F.
2 5 The data received starts with a specific character, and ends with a specific character. The setting value in D +1 2 is a specific start character, and a specific end character. If a start character is 16#3A, and a stop character is 16#0A, the value in D +1 will be 2 16#3A0A. 6 A specific quantity of data is received. The setting value in D +1 2 is the length of the data which is received. If users want to receive 10 characters, the value in D +1 is 10. 2 Others If the mode used is not a mode which is supported, the instruction will not be executed. Communication COM1 COM2 Remark port number SM98 SM99 When the PLC receive data, it sets a reception flag to ON.
After the receiving of data is complete, the PLC will reset the reception flag to OFF. Reception flag SM100 SM101 When the receiving of data is complete, the PLC sets a completion flag to ON. Users have to reset the completion flag to OFF by means of a program. After the completion flag is reset to OFF, the PLC will wait for the next Completion flag