gar
Stainless
- Joined
- Feb 17, 2005
- Location
- Ann Arbor, Michigan USA
I am current looking a Xmodem communication to and from HAAS using Hyperterminal.
Settings at HAAS 115.2 kbaud, 8 data bits, parity none, 1 stop bit, and obviously Xmodem which means no hardware, or Xon-Xoff, or DC codes.
Same settings at IBM PC in HyperTerminal and FIFOs disabled.
Sending from HAAS to PC the rate is about 2700 characters per second with no retries. The theoretical maximum thruput should be 115200/(1+8+1) = 11,520 characters per second. This has to be reduced by the overhead of header, checksum, and ACK --- 128 / (3+128+1+1) = 0.962 . So theoretical max is 11,520 * 0.962 = 11,082. Thus, thruput efficiency is 2700 / 11,082 = 24.4 %.
I do not remember the value but the other night I ran a test from HyperTerminal to HAAS. The efficiency was much better, but I believe below 50%.
My test file for transmission was about 170,000 bytes.
Is all the problem at HAAS, or partial, or not at all? How much of the problem is HyperTerminal?
Can anyone else confirm my results, and/or with a different communication program?
In non-Xmodem mode thruput is quite close to theoretical maximum using Cimco Edit.
.
Settings at HAAS 115.2 kbaud, 8 data bits, parity none, 1 stop bit, and obviously Xmodem which means no hardware, or Xon-Xoff, or DC codes.
Same settings at IBM PC in HyperTerminal and FIFOs disabled.
Sending from HAAS to PC the rate is about 2700 characters per second with no retries. The theoretical maximum thruput should be 115200/(1+8+1) = 11,520 characters per second. This has to be reduced by the overhead of header, checksum, and ACK --- 128 / (3+128+1+1) = 0.962 . So theoretical max is 11,520 * 0.962 = 11,082. Thus, thruput efficiency is 2700 / 11,082 = 24.4 %.
I do not remember the value but the other night I ran a test from HyperTerminal to HAAS. The efficiency was much better, but I believe below 50%.
My test file for transmission was about 170,000 bytes.
Is all the problem at HAAS, or partial, or not at all? How much of the problem is HyperTerminal?
Can anyone else confirm my results, and/or with a different communication program?
In non-Xmodem mode thruput is quite close to theoretical maximum using Cimco Edit.
.