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safety cover. If necessary, replace F3 with a 5x20 mm SLO-BLO fuse with a rating of 1 Amp 250V, e.g. Littelfuse P/N 218001. Be sure
to REPLACE THE SAFETY COVER on F3 before re-applying power to the DVP-120.
! WARNING
DVP-120 may not function effectively below 32°F (0°C). Using the instrument below this temperature may adversely affect product
performance and
result in sickness or death
.
4.4
LCD Display unreadable
It is possible that the LCD is unreadable due to temperature or aging of the control panel. If this is the case the following steps should
rectify the problem:
–
Hold the MENU key for three (3) seconds. After three seconds, the power led will turn red. After two additional seconds, the
LCD backlight will also be turned off.
–
Press the UP and DOWN cursor keys to change the LCD contrast. Each press of the UP or DOWN cursor key will change the
contrast by a step in that direction. Adjust the contrast for best viewing.
–
Press any other key to exit the contrast-setting mode.
4.5
The Keypad does not respond (LCD shows KEYS LOCKED)
The keypad can be unlocked by holding the zero (0) key for 3 seconds. At this time the backlight will turn on and the display will return
to normal mode. The keypad can again be locked by holding the zero key for 3 seconds, until the display shows KEYS LOCKED.
4.6
The Keypad does not respond after silencing an Alarm, Warning or Trouble.
LCD continues to show the alarm, warning or trouble message.
It is possible that the horn or strobe have been configured to respond in alarm, warning or trouble conditions, even though there is no
horn or strobe connected (or perhaps they are used for some purpose that is not audible or visible). First, hold the HUSH key for five
seconds, or until the display changes to “ALARM silenced for 5 minutes” or other relevant message. Second, use the configuration
menu to disable the horn or strobe, if they are not being used for some other purpose.
4.7
After a power failure
After any power failure, the user should check the system clock. While system parameters are maintained in memory, the system clock
is backed-up by a limited-capacity button cell battery.
4.8
MRS-485 Modbus Application
The MRS-485 will monitor the 4-20 mA current output of the detector. At power up and during its warm-up period, the 6-Series detector
will communicate its sensor type over the 4-20 current output using a custom protocol. The MRS-485 will automatically register each 6-
Series detector as it is programmed with information about all the detectors to which it can be connected. The MRS-485 will use this
information to determine the gas level sensed by the 6-Series detector by measuring the 4-20 mA current-loop output during normal
operation of the detector.
Normal Operation
1. When the LED is solid GREEN, operation is normal, the MRS-485 knows the detector type, no errors are detected and no MODBUS
data are being received or transmitted over the RS-485 line.
2. When the LED is GREEN with random bursts of AMBER, operation is normal and now data are being received or transmitted over
the RS-485 line. The AMBER LED will come on anytime that there is data traffic.
Unknown Sensor Code
GREEN/OFF Alternating every 500 milliseconds - The MRS-485 doesn’t know the detector type, no MODBUS communications is in
progress and no errors are detected.
To correct this condition:
1. Disconnect the power line from the MRS-485.
2. Disconnect the MODBUS line from the MRS-485.
3. Re-connect the Modbus Line to the MRS-485.
4. Re-connect the power line to the MRS-485.
