Hitachi EH-150 Applications Manual page 125

[ Rough estimate of response time ]
Calculate the rough estimate value of the response time of the ASR communocation by the following.
Response time : 30ms * T
T : Count of internal processing
- Calculation method of T : T = T
(1) Send area
The count of internal processing is calculated by each item on both word and bit.
- Word data T : (Number of send data) / 120
SW
(Example) Number of send data = 200 words : T = 2 (200÷120)
- Bit data T : (Number of send data) / 240
SB
(Example) Number of send data =200 bits : T=1 (200÷240)
(2) Receive area
At 1 connection : T
(Example) Number of receive data = 120words : T=2 (120÷100)
［ Example of response time］
The response performance of the ASR I/O area setting in table A.3 is shown below.
- Send time of word data
T = (200÷120) + (200÷120) + (200÷120) + (200÷120) + (200÷120)
SW
= 2 +
= 10
- Send time of bit data
T = (1÷240) + (1÷240) + (1÷240) + (1÷240) + (1÷240) + (1÷240) + (1÷240) + (1÷240)
SB
= 1 + 1
= 8
- Receive time
T = (200÷100) + (200÷100) +(200÷100) +(200÷100) +(200÷100) +(200÷100)
R
= 2 +
= 12
T== T + T + T = 10 + 8 + 12 = 30
SW SB R
Response time = 30ms * T = 30ms * 30 = 900ms
Therefore, response time becomes 900ms.
*) Set the ASR I/O area so that the response time may become within about 80% at a cyclic time at a cyclic
transmission.
Connection No.
Number of receive data
Item No.1
Item No.2
Item No.3
Item No.4
Item No.5
Item No.6
Item No.7
Item No.8
Item No.9
Item No.10
Note: The column of the blank in the table is set no data.
+ T + T
SW SB R
: (Number of receive data)÷100
R
2 + 2 +
+ 1 + 1
2 + 2 +
Table A.3
1 2
200 words 200 words
1 bits 200 words
1 bits
1 bits
1 bits
1 bits
1 bits
1 bits
1 bits
A-2
Appendix A Response performance
( It rounds up below the decimal point )
( It rounds up below the decimal point )
( It rounds up below the decimal point )
2 + 2
+ 1 + 1 +
2 + 2 +
ASR I/O area setting
3 4
200 words 200 words
200 words 200 words
1 + 1
2
5 6
200 words 200 words
200 words 200 words