Rice Lake Signal Conditioning Transmitter/Indicators User Manual

Page 59

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Operation 55

Tare Weight Zero Setting

The PC transmit the following ASCII string containing the zeroing command:
$aazckckCR

$01z7BCR

in which:

z = weight zeroing command (122 ASCII)

Possible instrument responses:

- correct reception: &aaxxxxxxt\ckckCR
- incorrect reception: &&aa?\ckckCR
- If the instrument is not in gross weight displaying condition, the

response is: &aa#CR

in which:

xxxxxx = 6 characters for the required weight value;

t = weight identification code (116 ASCII).

Example: Weight zero setting for instrument with address 2:
For the calibration, make sure that the scale is empty and the instrument measures a corresponding mV signal.

query: $02z78(Cr) response: &02000000t\76(Cr)

In case of correct weight zero setting the read value (response) must be 0 (in the string “000000”).

The zero values are stored to the EEPROM memory, please note that the number of writes allowed is
limited (about 100000). If it is necessary to reset the weight quite often, it is recommended to perform it
by PC or PLC program, keeping in mind the weight deviation respect to the zero instrument.

Weight (Span) Calibration (With Test Weights)

After having performed the TARE WEIGHT ZERO SETTING, this function allows correct calibration to be done

using test weights of known value and, if necessary, any deviations of the indicated value from the correct value to

be corrected.
Load the test weight onto the scale, use as high a percentage of the maximum quantity to be weighed as possible.

Otherwise make sure that the instrument measures a corresponding mV signal.
The PC sends the following ASCII string containing the calibration command:

$aasxxxxxxckckCR

in which:

s = calibration command (115 ASCII)

xxxxxx = 6 characters for test weight value.

Possible instrument responses:

- correct reception: &aaxxxxxxt\ckckCR
- incorrect reception or full scale equal to zero: &&aa?\ckckCR

in which:

t = gross weight identification code (116 ASCII).

xxxxxx = 6 characters to indicate the current weight value.

In case of correct calibration, the read value must be equal to test weight.

Example: Calibration for instrument with address 1 and test weight of 20000 kg:

query: $01s02000070(Cr) response: &01020000t\77(Cr)

In case of correct calibration the read value has to be “020000”.

Important

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