SATEC 1771DB - Manual (Page 9)

9
2. The phase A reactive power of value -130,750 kvar is transferred as:
word 34 = 750
word 35 = 13
word 36 = 1
The actual value is - (13*10000 + 750) = -130,750
Total active power is transferred only for positive values. In the case of the negative total
power, the value will be zeroed.
4.1.2 Error Reporting
When the E option is used, the status of the instrument being polled is always reported in word
64 of the BTR buffer. When reading the BTR buffer, the processor should check this word
before applying data. The value of 0 shows the data in the BTR buffer is OK. When the
BASIC module fails to receive data from the instrument, a non-zero error code is written to
word 64 accompanied by the instrument address in word 1. All other words will be zeroes.
The possible error code values are shown in Table 4-1.
Table 4-1 Error Codes
Error code (word 64) Description
0 No errors found
1 The instrument doesn't respond
2 Check error (framing or check field error is detected)
4.2 Writing Data to the BASIC Module
When the R option is used, the driver allows the processor to reset accumulated energies and
demands in the selected Powermeter, or synchronously in all Powermeters on line, if this
function is supported by the instruments. The processor request is transmitted to the BASIC
module via the BTW buffer. The BTW buffer structure is shown in Table 4-2.
Table 4-2 BTW buffer structure
Field No. Field Name BTW buffer
word Range Description
1 Instrument address 1 0-31 0 = all the instruments
2 Command 2 1-2 1 = Reset accumulated energies
2 = Reset maximum demands
The instrument address value of 0 will apply to all the instruments connected to the BASIC
module.
The command value of 1 will result in resetting the active (+kWh), returned (-kWh) and
reactive (kvarh) energies. The command value of 2 will reset the active power maximum
demand, apparent power maximum demand, and all of the ampere maximum demand values.
The command value of 0 has no action.