Pulsafeeder Pulsar DLC - Manual (Page 52)

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7.2.5 MODBUS Signal Failure Setup
This sub-menu allows you to set up the DLC response if the MODBUS Signal fails. You can program
the DLC to have one of the following responses:
− Freeze at the last digital input signal,
− Shut the motor off,
− Go to a default setting.
A MODBUS Signal failure is detected if the DLC does not receive a valid message sent to its address
within the timeout setting.
v
Setting up the DLC response.
1. Press [MENU] and press [UP] or [DOWN] until the display reads {–MENU– / MODBUS SIG. FAIL}.
–MENU–
MODBUS SIG. FAIL
Press [ENTER] to continue to the MODBUS Signal Fail sub-menus.
2. The {RESTORE TO:} menu is displayed. This setting determines how the DLC will recover from a
failed MODBUS Signal. You can select from two {RESTORE TO:} modes – MODBUS or Manual.
If {MODBUS MODE} is selected the DLC will resume following the MODBUS signal automatically
when the signal is restored.
If {MANUAL MODE} is selected, the DLC will enter manual mode as soon as the signal loss is
detected. The DLC will remain in Manual Mode until it is changed manually (press [MODE] on the
front panel).
The benefit of using {RESTORE TO: / MODBUS MODE} is that it’s totally automatic. If so
programmed, the DLC can shut itself down, wait for the signal to return and then start itself back up.
Press [ENTER] to accept the factory default of {RESTORE TO: / MODBUS MODE} or press [UP]
and then press [ENTER] to select the {RESTORE TO: / MANUAL MODE}.
RESTORE TO:
MODBUS MODE Press
[UP] RESTORE TO:
MANUAL MODE
3. The next entry in the MODBUS SIG. FAIL sub-menu allows you to set the timeout value in seconds.
This defines the maximum interval between messages addressed to this node. If a message is not
received within this period, a MODBUS Signal failure will be detected. A number of factors influence
the value you should set here:
a) Number of nodes on the network.
b) Type of master.
c) Baud rate.
d) Electrical environment.
Here are some general guide lines:
− Increase this value as you increase the number of nodes on the network.
− Increase this value as you decrease the communications baud rate.
− Increase this value if the DLC is a slave connected to a heavily loaded PC/PLC master.
− Increase this value if you are in an electrically noisy environment.
− Decrease this value if the DLC is mission critical on a small (2-3 node) network.
Always use the default setting (2.5 seconds) as a starting point. To adjust the value, press [UP] or
[DOWN]. Press [ENTER] to accept the value.
TIMEOUT
2.5 SECONDS