Spectrum Controls 140 MPM 204 00sc User Manual

Page 33

Meter Proving Module

Load

Load Scale/Limit

Scale/Limit

Scale/Limit W

Word:

ord:

ord: Bit 1

Bit 1

Asserting this bit enables register 4X+1. The value in register 4X+1 is defined by the Channel

Number bits and the Parameter Definition bits.

If the customer desires to update the K, M, R, or rate limit values the enable scale/limit word

bit must be set. The default values for all of these scaling and limit words is initially 0. Program-
ming these values in EEPROM so that the values will need to be stored only once. The module will
retain these values even if power is removed.

Layout for 4X+1 Register

The 4X+1 register is used to set the Rate Limit, M scale factor, K scale factor, and R scale

factor for each channel as explained in table Module Configuration Word (4X+0 Registers). These
scale factors are explained as follows:

Rate Limit

Rate Limit
When the Rate limit value other than 0 is present the data value in this register can be used as

an upper frequency limit and annunciated via the Rate Limit Status Flag. To write the value to
EEPROM the Program EEPROM bit must be toggled from a zero to a one.

M Scale Factor:

M Scale Factor:
In Program Mode the data value in this register is used for scaling. The Scale data can be

stored in EEPROM. To store the scale data in EEPROM valid data must be place into this data
register. When the Program EEPROM bit toggles from a zero to a one, data in the Scale Register
will be written into the modules EEPROM. The M scale factor is used for meter calibration. When
a non-zero Scale Factor value is set the scale calculation is always performed. A value of zero must
be written to the Scale Factor to disable this feature.

The M factor value expressed as a 16 bit unsigned integer divided by 10,000. This value is

multiplied by the counter actual count value, and gives the M factor a range of 0.0001 to 6.5535
Most M factors will be within +- 5% of 1.0000.

K Scale Factor:

K Scale Factor:
The K scale factor is used for flow meter scaling. This allows users to scale the meter output

into more useful units, like gallons. When a non-zero Scale Factor value is set the scale calculation
is always performed. A value of zero must be written to the Scale Factor to disable this feature.
This counter value is divided by the K factor. K factors are be positive numbers.

When a non-zero K factor is programmed into EEPROM, K divides the physical counter value.
Counter Output Value = Actual Counter Value / K.

R Rate Factor: