Version 3.4
20
NC-217
Operating manual
2.3.4
Recommendations on output ports rate
2.3.4.1
Output interface capacity shall meet the following condition: sum of input
data streams per time unit shall be less than channel capacity.
Output data baud rate shall be higher than value of output channel capacity, which
is calculated using the following formula
n
n
n
f
C
)
(
E
,
(1)
where
n
– a number of input channel;
С
n
– size of message on channel
n
;
f
n
– transmission frequency on channel
n
;
E – required capacity of output channel in byte/s.
Since there are various options for data coding in serial transmission, then under the
following conditions required capacity bit per second shall comply with the parameters de-
scribed in table 4.
Table 4 – Capacity value under various options of coding
Stop bits
Parity
Capacity
1
No
Е * 9
1
Even or Odd
E * 10
2
No
E * 10
2
Even or Odd
E * 11
Max. output channel capacity is 115200 bit or 14400 byte; it is recommended to use
not more than 90% of channel capacity 102400 bit or 12800 byte.
2.3.4.2
To calculate output channel capacity, it is necessary to sum data on three input
channels and parameters represented in table 5.
Table 5 – Parameters to calculate output channel capacity
Channel №
Size of message, byte
Transmission frequency, Hz
1
50
10
2
30
5
3
100
1
Therefore, output channel capacity shall make:
E = (50 * 10) + (30 * 5) + (100 * 1) = 750 byte/s.
For the output port set parity – “No”, number of stop bits – 1. Then output channel
capacity shall be at least:
E = 750 * 9 = 6750 byte/s.
Hence, output port rate shall be set at least 7200 byte/s; output port rate is selected
in available settings of the Product.
