Halma Alicat Scientific IVCD, Руководство по эксплуатации

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12 Control
Control
Changing the Setpoint
SETPT or MENU → CONTROL → Setpt:
The setpoint selection screen indicates the engineering units and maximum allowable
setpoint (e.g., PSIG: +10.000 Max). To cancel a setpoint, press
CLEAR
, then
SET
.
Adjusting Setpoint with an IPC
For controllers ordered with a potentiometer control knob (IPC), the setpoint source must be set to analog for the controller
to receive setpoint commands from the IPC (see “Changing Between Setpoint Sources” below).
Leave the IPC knob at the midpoint when it is not in use.
Setpoint Setup
Using Autotare
CONTROL → Setpoint Setup → Zero Setpoint
When the setpoint is zero, the controller will automatically tare itself if autotare is enabled. This menu also specifies how
many seconds after a zero setpoint the controller will wait, under
Delay Before Tare
.
▲
Caution: Auto-tare is typically not recommended for pressure control applications.
Setpoint ramping ( page 14 ) can either be set to honor the ramp rate limit or to go to zero as quickly as possible.
Changing Between Setpoint Sources
CONTROL → Setpoint Setup → Setpoint Source
Pressure controllers with RS-232 or RS-485 communication will accept setpoints from the front panel and serial commands
( page 18 ), or from an analog signal.
• When the source is set to
Serial/Front Panel
, the controller will accept input from either the front panel, or an RS-232/
RS-485 connection. Neither source is a slave of the other, so the controller will accept the most recent command
from either source.
• When the source is set to
Analog
, the device ignores serial setpoint commands and will prevent setpoint input from
the front panel.
Managing Setpoint with an Idle Modbus Connection
CONTROL → Setpoint Setup → On Modbus Timeout
If a Modbus connection is idle for a specified amount of time, the device can be configured to set a zero setpoint, or
maintain the previous setpoint. The idle time will be infinite by default and can be adjusted ( page 16 ).
Managing Setpoint on Power-Up
Power-Up Setpoint Value
CONTROL → Setpoint Setup → Power Up Setpoint → Value
By default, the controller remembers its last setpoint across power cycles. However, it can be changed to give a specified
setpoint upon power-up by selecting
Fixed Setpoint
and entering a value. If the setpoint will be digitally provided more
often than every few minutes, use a fixed setpoint on power-up to avoid wearing out non-volatile memory in the device.
Power-Up Setpoint with Ramping
CONTROL → Setpoint Setup → Power Up Setpoint → Ramp
Any setpoint ramp will always start from zero on power-up. Similar to the zero setpoint option ( page 16 ), the device
can either honor the ramp rate (
Honor from 0
) or jump to setpoint (
Jump from 0
) as quickly as possible.
The control menu .