CET Electric Technology
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(592 days x 24 hours per day x 4 data records per hour). In order to do this, it’s necessary to free the log
memory occupied by Data Recorders #2 to #5 by setting their respective Number of Parameters and
Recording Depth setup parameters to 0.
The PMC-53A-E’s Data Recorder has been enhanced such that it can support a maximum Recording
Depth of 120,000 records (compared to the max. of 10,000 in PMC-53A), which is equivalent to 1250
days (~3.4 years) of recording at 15-minute interval. However, only one Data Recorder can be configured
with a maximum of 6 parameters and 120,000 records.
The following formula can be used to calculate how many bytes would be required for a single record
with n parameters where 0 ≤ n ≤ 16.
No. of Bytes per Record = n x 4 + Timestamp @ 8 bytes
With 16 parameters, the no. of bytes required = 16 x 4 + 8 = 72 bytes. If a Data Recorder is allocated a
single 800kB buffer, its Recording Depth = 800kB / 72 bytes = 11,377 records.
It should be noted that the above calculation is used to illustrate the internal organization of the data
storage and is only an approximation of the actual implementation. The following table defines how
many records are actually available for the different number of parameters in each 800kB buffer.
No. of Parameters
No. of Records
No. of Parameters
No. of Records
1
68,200
9
18,600
2
51,200
10
17,000
3
40,800
11
15,600
4
34,000
12
14,600
5
29,200
13
13,600
6
25,600
14
12,800
7
22,600
15
12,000
8
20,400
16
11,200
The programming of the Data Recorder is only supported over communications. Each Data Recorder
provides the following setup parameters:
Setup Parameters
Value/Option
Default
Trigger Mode
0=Disabled / 1=Triggered by Timer
1
Recording Mode
0=Stop-When-Full / 1=First-In-First-Out
1
Recording Depth
1 to 120,000 (entry)
5760
Recording Interval
60 to 3,456,000 seconds
900 s
Offset Time
0 to 43,200 seconds, 0 indicates no offset
0
Number of Parameters
0 to 16
16
Parameter 1 to 16
See Appendix A for a complete list of parameters
See Appendix B
Table 4-13 Setup Parameters for Data Recorder
The Data Recorder Log is only operational when the values of Trigger Mode, Recording Depth,
Recording Interval, and Number of Parameters are all non-zero.
The Recording Offset parameter can be used to delay the recording by a fixed time from the Recording
Interval. For example, if the Recording Interval parameter is set to 3600 (hourly) and the Recording
Offset parameter is set to 300 (5 minutes), the recording will take place at 5 minutes after the hour
every hour, i.e. 00:05, 01:05, 02:05, etc. The value of the Recording Offset parameter should be less
than the Recording Interval parameter.
4.6 Time of Use (TOU)
TOU is used for electricity pricing that varies depending on the time of day, day of week, and season.
The TOU system allows the user to configure an electricity price schedule inside the PMC-53A-E and
accumulate energy consumption into different TOU tariffs based on the time of consumption. TOU
programming is only supported through communications.
The TOU feature on PMC-53A-E supports two TOU schedules, which can be switched at a pre-defined
time. Each TOU schedule supports:
Up to 12 seasons
