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BurstSE(1735)
DataTable
(BurstSETable,True,-1)
Sample
(1735,BurstSE(),FP2)
EndTable
BeginProg
Scan
(1,sec,10,0)
'Negate the measurement channel to make a burst measurement
CDM_VoltSe
(VOLT108,1,BurstSE(),1735,mV5000,-1,False,150,15000,1,0)
CallTable
BurstSETable
NextScan
EndProg
10.4.2 CPI network bit rate
A CPI network is capable of operating at 1000, 500, 250, 125, or 50 kbps, depending on your
network configuration (see
the rate that data are transferred from the GRANITE Measurement Module to the data logger.
When multiple GRANITE Measurement Modules are making measurements faster than 1 Hz, it is
important to ensure that the CPI network bit rate is higher than the rate that data is generated by
the GRANITE Measurement Modules within the network.
To calculate how many kilobits per second (kbps) will be generated, use the following equation
for each GRANITE Measurement Module in your network:
Kilobits per second = (number of measurements) × (measurement frequency) × (0.064 kilobits
per measurement)
The network topology and cable length affect the maximum allowable CPI network bit rate. Refer
to
Table 10-2
(p. 36) for the maximum cable length allowed for the topology and bit rate your
network requires. The bit rate of the network defaults to 250 kbps and can be changed by using
CPISpeed()
the
instruction in the data logger program.
Table 10-2: Network topology, bit rate, and cable length
Bit Rate1 (kbps)
1000
500
CRBasic Example 3: Measuring VoltSE() in burst mode
Connecting multiple GRANITE Measurement Modules
Daisy-chain topology
Full termination
50
200
Maximum total cable length (ft)
Half termination
1
200
(p. 26)). This is
Star topology
No termination
not viable
100
VOLT 100 series
36
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