Beck, R&J ELECTRIC ACTUATORS FOR INDUSTRIAL PROCESSCONTROL 11-1_9 用户手册

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DCM-2 HART INTERFACE
 
Maintenance - Alarm Messages
COMMON HART
®
 MESSAGES
 HART
®
 protocol maintains both standard and 
device specific informational messages that are 
displayed on the 275/375 Handheld Communicator 
when various conditions occur.  They can also 
be used to trigger alarms and messages in other 
HART
®
 compatible monitoring systems.  These 
messages alert the user to various alarm conditions 
and make it much easier to diagnose problems.  
Below is a table of typical Beck drive messages 
and message sequences.  It does not include all 
possible messages, only the most common.
Handswitch and Limit Switch Messages
Message
Description
“Motor power is blocked, check switches” This message will appear if a condition prevents current flow to 
the motor.  Some of the most common conditions are:  The drive 
Handswitch is put in the STOP position; either of the drive over-
travel limit switches are open; or the motor control triacs fail.
Demand Signal and Process Variable Messages
Message
Description
“Process applied to the non-primary 
variable is outside the operating limits of 
the field device”
“The Demand Signal is outside of the 
intended limits (see Demand Setup 
menu)”
“Demand out of accurate measurement 
range”
This is a standard HART
®
-defined message that appears whenever 
one of the three HART
®
 non-primary variables (Demand signal, 
Torque, Temperature) are outside their design or calibrated ranges.  
The Demand input signal to the drive is typically the problem 
source; however, the message can also appear if either the torque 
measurement (optional) or temperature measurement is outside 
the design or calibrated ranges.  The Beck specific messages 
below provide more descriptive information.
This is a Beck-specific message that can appear after the HART
®
-
defined message above.  It specifically pinpoints the Demand input 
signal to the DCM-2 as the problem source, and indicates that 
the signal is outside the calibrated range limits.  The lower limit 
is configurable as a percentage of the calibrated range (default 
is -5%).  The upper range is the highest readable input voltage 
(5.5 VDC) expressed as a percentage of the calibrated range 
(e.g., approximately 112% for a 4–20 mA* or 1–5 V dc standard 
input range).
This is a Beck-specific message that can appear after the “Demand 
signal out of range” message above.  It further defines the demand 
signal problem by indicating that the signal is not only out of the 
calibrated range, but also out of the design range of the drive.  The 
lower and upper limits are 0.1 V dc and 5.55 V dc respectively.*
*Note that current input DCM-2 boards utilize a 250 Ohm input resistor to convert the current signal to voltage.