2. OPERATION
Output sentence limitation
The number of sentences which can be output depends on baud rate and output interval settings. The maximum number of characters per each data sentences are shown in the table below and the total number of characters must satisfy the formula shown below. The number of characters which can be output “N” is calculated by the following formula
N < 0.083 x T x B
T:Interval (s)
B:Baud rate
Sentence and maximum number of characters
Sentence | HDT | HDM | ROT | ATT | HVE | VTG* | GGA* | GNS* | GLL* | ZDA* | VHW* | VBW* | VDR＊ | |
No. of | 19 | 19 | 21 | 34 | 23 | 46 | 66 | 62 | 47 | 36 | 44 | 45 | 35 | |
Characters | ||||||||||||||
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*: Output is 1 s if interval set is shorter than 1 s.
For example, the baud rate is 4800 bps, interval is 100 ms (= 0.1 s). Therefore, the number of characters is N <0.083 x 0.1(s) x 4800(bps) = 39.4.
Then, the number of characters which can be output is 39. For sentences (sentences not having an asterisk in the table) where the output interval is variable the number of characters is as shown in the table, however sentences where the output interval is not smaller than 1 s
For the above settings the following applies:
•If both HDT and HDM are selected the total number of characters is 19+19 = 38. Since the count is less than 39 both can be selected.
•If both HDT and VTG are selected the total number of characters is 19+46x0.1=23.6. Since the count is less than 39 both can be selected.
•If HDT, HDM and VTG are selected the total number of characters is 19+19+46x0.1=42.6. In this case, the message “SENTENCE OVERLOAD” appears.
