Milltronics ACCUMASS BW500 - mA I;O (0;4-20 mA); Relay Output

PL-565 Accumass BW500 Page 91
Operation
mA I/O (0/4-20 mA)
Output
The standard BW500 provides one isolated mA output. The output can be assigned
(P201) to represent rate, load or speed. The output range can be set to 0 - 20 mA or
4 - 20 mA (P200). The 0 or 4 mA value corresponds to empty or zero condition,
whereas the 20 mA value corresponds to the associated design value: rate (P011),
load (P952) or speed (P014). 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 215 respectively) to agree with a
milliammeter or other external mA device.
The mA output value can be tested to output a prescribed value using parameter
P911. Refer to P911 on page 85.
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 control, output 2 is assigned to PID control loop 1 and output 3
is assigned to PID control loop 2.
Input
The optional mA I/O board provides two mA inputs, programmable as inputs 1 and 2.
If programmed for PID control, generally, input 1 is assigned to PID control loop 1
and input 2 is assigned to PID control loop 2.
The input range can be set to 0-20 mA or 4-20 mA (P250), and assigned a function
(P255), e.g. PID setpoint. The 4 and 20 mA levels can be trimmed (P261 and P262)
to agree with an external device.
Relay Output
The BW500 offers five single pole single throw (SPST) relays that can be assigned
(P100) to one of the following alarm functions:
• rate: relay alarms on high and/or low material flow rate.
• load: relay alarms on high and or low belt load.
• speed: relay alarms on high and/or low belt speed.
• diagnostic: relay alarms on any error condition as it is reported.
Refer to Troubleshooting on page 137.
• PID: PID control setpoint deviation*
• batch pre-warn
• batch setpoint
*is offered only if the PID system (P400) is enabled.
For rate, load and speed alarm functions, the high and low alarm setpoints (P101 and
P102 respectively) are required and must be entered in the appropriate units. The
high alarm setpoint acts as the setpoint deviation alarm for relays programmed for
PID setpoint deviation.