AW Gear Meters EMO-3000 - Manual (Page 14)

EMO‐3000
Operation and Programming Manual
13
ma‐Scaler The milliamp scaler scales the 0 ‐ 20 mAmp input signal on Pin 5 and 6 to the flow rate in
engineering units/mA.
For example: 20mA = 1000 cc/min. Then,
1000 = mA‐Scaler
B
where B = 20mA ‐ mA offset value.
With a mA Offset Value of 4mA, then mA‐Scaler = 62.5 cc/min or 1mA = 62.5 cc/min.
This signal serves as a flow rate setpoint in the PID mode after scaling.
mA’s offset Used in a situation where there is not an exact 4 mA’s at the low point of the analog
input. The offset is the base line for calculating the set‐value based on the analog input.
Important Hardware Connections for PID Operation
None of the following external signals has to be wired. However, they are useful features in PID mode.
See Appendix P for details.
Transparent The transparent input redirects the analog input, (PINS 5/6) directly to the mAmps
output (PIN 7). It is necessary to use the transparent input if the channel is put in open loop simulation.
This signal is located at PIN 11 on the backplane.
Hold Analog This input signal holds the analog output at the last set output. The hold input is often
used in flush situations where the controller is supposed to be disabled. This signal is at PIN 12.
Hold total Hold total input disables the totalizer. Often used during flush or soft‐air push cycles.
This signal is at PIN 13 on the backplane.
Set‐value You must program this number in order to generate a flow rate in PID if the external 0‐
20 mAmp set value is not hooked up. This is the digital set‐value. It is important to know that the analog
input set‐value is overridden.
Set reached An output that activates when the flow rate meets the set‐value (+/‐ tolerance). This
signal is at PIN 14.
Fluid Tables: The EMO‐3000 supports 32 fluid tables. Each table is externally accessed via pin #8 or
via the DM‐3000. The default fluid number is 00. Most variables affect all 32 fluid numbers, but a few
require that you enter the fluid number when they change. In this event, an additional screen appears
with prompts. You can assign each fluid table to store flow data for a different fluid or color as it is being
regulated. These data tables are continually adapted as each color is encountered. Each fluid is
identified by a voltage of 0.15625 volts, which represents 5 V divided by 32. For example, the first
color/fluid is indicated by the step voltage 0‐0.15625 V. See the fluid table illustration on page 22.