Install

* clear min/max (register 41021): The Modbus registers for rate-inst, rate-min and rate-max may be cleared by writing to a
Modbus register. It is assumed that these three fields will be cleared at the beginning of each new logging period by the
Modbus master device. In pulse mode, clearing the inst register does not clear the pulse count history. The fields for
inst/min/max will be valid after only one pulse value is received.
* average rate: (not an A8332-8F2D datapoint) The AcquiSuite will compute an average rate for the pulse count input.
The calculation will be performed at the end of each logging cycle by subtracting the count at the start and end of the interval
and dividing by the interval length. (DV/DT). This will provide the average rate over the log interval. If the unit of measure
is power related, (kwh, kvarh, kvah, etc) the average rate will be called "demand" as it is the effective block demand value
for the input. Because the rate value is not a Modbus register, Modbus master devices must use the “count” register and
compute the average rate value.
Status Mode:
count: the number of pulses counted on the input port. In standard mode, the pulse is counted on the closure of the contact.
If the KYZ option is enabled, both the closure and opening of the pulse are counted. The maximum pulse rate to be able to
count is 10 Hz. Expect pulse width to be minimum of 20ms.
on-time: the cumulative number of seconds the contacts have been closed. The pulse count starts at zero (factory default)
and always increments as pulses are counted. Rollover at 2^32 (over 130 years). Count is stored in nv memory. This value
has 1 second granularity, rounding is performed by sampling the input once per second and accumulating 1 second if the
contact is closed at that time. For practical applications, the pulse width should be a minimum of 1 second.
dutycycle: The ratio of of time the contact is closed vs open. For example, if the contact is closed for 10 seconds and open
for 30, the dutycycle register will report 25%. The register value returned must be divided by 1000 to convert it to a
percentage with three decimal places.
status: returns 1 if the contact is presently closed, 0 if the contact is presently open.
* clear min/max (register 41021): the only value cleared in status mode is the dutycycle field. The data logger will clear this
field at the beginning of each log period. The dutycycle register will be used to calculate the dutycycle for one log period
only.
Voltage Mode, Current Mode, Resistance Mode:
(all 3 modes are the same unless otherwise noted)
instantaneous: The instantaneous reading will report the present status of the input, represented in ohms, mA, or volts. The
value uses a short term average of the last 16 a/d converter readings to compute the value of this register. In voltage and
current mode, the instantaneous value is calculated several times per second. In resistance mode, the value is calculated at
least every two seconds. 0xFFFFFFFF will report an off-scale-high condition, or any other invalid data.
average: This register reports the longer term average of the input. Each time a short term average is calculated with all-new
samples, the value is added to the cumulative average. This value should be reset using the clear min/max register at least
once per hour. If not cleared, it will eventually start a moving average after memory storage is exceeded. The AcquiSuite
will clear this register at the start of each data logging period.
min: the minimum value seen in the instantaneous register.
max: the maximum value seen in the instantaneous register.
* Multipliers: The register value for inst, average, min, and max must be divided by 1000 to convert the number to mA and
Volts. Volts mode reports 0 to 10.000V. Current mode reports 0 to 20.000mA. In resistor mode value is reported in ohms
and no division is required. Note: in current mode, the broken-wire register 40074 is set when the input goes below 4mA,
however the current value reading will still be shown in the data register. Modbus master systems should typically discard
readings below 4mA as broken-wire/invalid when reading a 4-20mA sensor.
* clear min/max (register 41021): This register clears the values for average, min, and max. The historical accumulation of
samples for the average field will be cleared, and average, min, max will be set to the present instantaneous value after the
next instantaneous value is recalculated.
Page 11 A8332-8F2D