ProtEX PD8-6080/PD8-6081 Explosion-Proof Modbus
®
Scanner Instruction Manual
76
Troubleshooting
D
ue to the many features and functions of the scanner, it’s possible that the setup of the scanner does not
agree with what an operator expects to see. If the scanner is not working as expected, refer to the
recommendations below.
Symptom
Check/Action
No display at all
Check power at power connector
Not able to change setup or
programming,
Locd
is displayed
Scanner is password-protected, enter correct six-digit password to unlock
Scanner displays error message
during scaling (
Error
)
Check:
Input 2 must greater than Input 1, Input 3 must be greater than
Input 2, etc.
Scanner displays
1.
999999
2.
-99999
Indicating overrange or underrange condition
Check the input data value and scaling in
Setup
menu
Display stop scanning,
■LED
indicator flashing
Check:
1. Stop on alarm feature has been enabled
2. Press PREV or NEXT to resume scanning
Displays
break
message
Check:
1. RS-485 connection to slave devices
2. Slave Id, register number of slave devices
3. Baud rate and parity of all devices on the bus
4. Scanner Id must be different from other devices
Snooper mode not reading the
PVs on the RS-485 bus
Check:
1.
Increase Master’s Transmit Delay
(e.g. Snooper delay = 100ms, Master delay = 110ms)
2.
Increase Snooper’s byte-to-byte timeout
3.
Decrease the slave device’s transmit delay to <10ms
4. Snooper cannot read the same PV twice, check setup
Scanner experiencing faults and
communication breaks
Check:
1. Increase response time (
t-resp
) and/or transmit delay (
tr
dly
). This may require some trial and error, as these are
dependent upon the number of devices on the bus.
2. Internal Scan ID Modbus address. Addresses 256 (mA) or
257 (V) are used for Channel A, while Addresses 258 (mA)
or 259 (V) are used for Channel B.
Scanner not communicating with
ScanView software
Check:
1. Serial adapter and cable
2. Serial settings
3. Scanner address, baud rate, and transmit delay
Display does not respond to input
data, reading a fixed number
Check:
Display assignment, it might be displaying max/ min
Display reading is not accurate
Check:
1. PV Scaling
2. Check format selected: Dec or Ft&In
Relay operation is reversed
Check:
1. Fail-safe in
Setup
menu
2. Wiring of relay contacts
Relay and status LED do not
respond to signal
Check:
1. Relay action in
Setup
menu
2. Set and reset points
Flashing relay status LEDs
Relays in manual control mode or relay interlock switches opened.
If the display locks up or the
scanner does not respond at all
Cycle the power to reboot the microprocessor.
Other symptoms not described
above
Call Technical Support for assistance.