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7ML19985CN01
Milltronics SF 500 - INSTRUCTION MANUAL
Page 49
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Oper
ation
Operation
Rate Sensing
For the SF 500 to calculate rate and totalize material flow through the flowmeter, a rate
signal representative of material flow is required. The rate signal is provided by the
flowmeter. The SF 500 is compatible with flowmeters fitted with one or two strain gauge
type load cells. To function with LVDT type sensors, an optional LVDT conditioning card is
required.
Refer to
Specifications
on page 3 for flowmeter requirements, and
Interconnection
on
page 9 for the proper connection.
Damping
Damping (P080) provides control over the speed at which the displayed rate reading and
output functions respond to changes in the internal rate signals. The damping controls
change in the displayed rate of material flow. Relay alarm functions based on input
functions of rate respond to the damped value.
Damping consists of a first order filter applied to the signal (reading or output value).
If mA damping (P220) is enabled (value other than 0), then the damping (P080) as it
pertains to the mA function is overridden, and responds independently at the specified
mA output damping rate (P220).
mA I/O (0/4-20 mA)
Output
The standard SF 500 provides one isolated mA output (P201). The output range can be set
to 0 - 20 mA or 4 - 20 mA (P200). The 0 or 4 mA value corresponds to no flow or zero
condition, whereas the 20 mA value corresponds to the associated design rate (P011).
The mA output can be limited for over range levels of 0 mA minimum and 22 mA maximum
(P212 and P213 respectively). The output 4 and 20 mA levels can also be trimmed (P214
and P215 respectively) to agree with a milliamp meter or other external mA device.
The mA output value can be tested to output a prescribed value using parameter P911.
Refer to
P911 mA Output Test
on page 116.
The optional mA I/O board provides two additional mA outputs, programmable as outputs
2 and 3, using the same parameters as the standard output (1). If programmed for PID
Note:
Damping (P080-01 or P220) is not applicable to the mA output when
programmed for PID function (P201 = 2).