Meter's Response Time - Omega DP41-B Series User Manual

9. Meter Bus Response

9.1.1 METER'S RESPONSE TIME

RESPONSE TIME: this is the period from the time the meter detects the first command
character to the time that it starts transmitting proper response.
Response time = Transmit command time + program delay time + turn around delay time.
Where:
Transmit Command Time = the transmission period of full command from the host
computer to the meter.
[(# of bits in a character) * (# of characters)] – [baud rate] (in seconds)
where: * = Multiply
# of bits in a character = 10 or 11 (see Sections 4.12 and 6)
Turn around delay = Receive to transmit delay and can be programmable to 0, 30,
100, 300 ms. For the following data turn around delay assumed 0.
TABLE 9.1 READING RATE FOR COMMAND MODE
Sample Rate
0 (slow)
1
2
3
4
5 (fast)
Test with Command Mode (Baud Rate at 19200 bps, Command Mode)
For the Command Mode, if the command-sending turn-around time is shorter than the
turn-around time in the above table (Refer to Process or TC), the response will have
some duplicate readings. For example, if the sample rate is 1 in process, the command
sending turn-around time should be larger than 68 ms.
Although single long transmission's delay seems longer than chunk
transmission, in most cases total transmission time will be shorter, especially
using 19200 baud rate.
Process (100mV) Rate (ms)
(Turn Around - Time ms)
7(135 ms)
14(68 ms)
27(36 ms)
52(19 ms)
60(14 ms)
60(14 ms)
9-2
TC(K type) Rate (ms)
(Turn Around - Time ms)
7(135 ms)
14(68 ms)
28(36 ms)
28(30 ms)
28(30 ms)
28(30 ms)