mscomm的最大传输速率是多少？

[gordonlj]

查询RS485的最大速率为10Mbps，但是mscomm中setting参数的传输速率最大为115200,
请问：1）mscomm能实现10Mbps吗？传输距离很近，10m内
2） mscomm的最大传输速率是多少？

[schlafenhamster]

参考 A look at the performance requirements at high bit rates shows why the 16, 32, 64 or 128 byte FIFO is a necessity. The Microsoft specification for a DOS system requires that interrupts not be disabled for more than 1 millisecond at a time. Some hard disk drives and video controllers violate this specification. 9600 bit/s will deliver a character approximately every millisecond, so a 1 byte FIFO should be sufficient at this rate on a DOS system which meets the maximum interrupt disable timing. Rates above this may receive a new character before the old one has been fetched, and thus the old character will be lost. This is referred to as an overrun error and results in one or more lost characters. A 16 byte FIFO allows up to 16 characters to be received before the computer has to service the interrupt. This increases the maximum bit rate the computer can process reliably from 9600 to 153,000 bit/s if it has a 1 millisecond interrupt dead time. A 32 byte FIFO increases the maximum rate to over 300,000 bit/s. A second benefit to having a FIFO is that the computer only has to service about 8 to 12% as many interrupts, allowing more CPU time for updating the screen, or doing other chores. Thus the computer's responses will improve as well.

[worldy]

哪家的RS485可以传输10Mbps，真是牛了，一般RS485都是基于RS232上的传输

[gordonlj]

引用 2 楼 worldy 的回复:

哪家的RS485可以传输10Mbps，真是牛了，一般RS485都是基于RS232上的传输

百度一下，都说是10M，所以想考证一下

[gordonlj]

引用 1 楼 schlafenhamster 的回复:

参考 A look at the performance requirements at high bit rates shows why the 16, 32, 64 or 128 byte FIFO is a necessity. The Microsoft specification for a DOS system requires that interrupts not be disabled for more than 1 millisecond at a time. Some hard disk drives and video controllers violate this specification. 9600 bit/s will deliver a character approximately every millisecond, so a 1 byte FIFO should be sufficient at this rate on a DOS system which meets the maximum interrupt disable timing. Rates above this may receive a new character before the old one has been fetched, and thus the old character will be lost. This is referred to as an overrun error and results in one or more lost characters. A 16 byte FIFO allows up to 16 characters to be received before the computer has to service the interrupt. This increases the maximum bit rate the computer can process reliably from 9600 to 153,000 bit/s if it has a 1 millisecond interrupt dead time. A 32 byte FIFO increases the maximum rate to over 300,000 bit/s. A second benefit to having a FIFO is that the computer only has to service about 8 to 12% as many interrupts, allowing more CPU time for updating the screen, or doing other chores. Thus the computer's responses will improve as well.

THX

[schlafenhamster]

RTS485 理论上，通信速率在100Kbps及以下时，RS485的最长传输距离可达1200米， 所以 10M 只是说说而已。