Omni8/16C/Omni8P User Manual
UMC1480R24.pdf
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© Omniflex 2021
5.8.1
Omni8/16C Fast and Slow Timers
Figure 5-1 above shows the use of the Fast and Slow timer. These timers allow the user the most
flexible timing options. For very short timing durations, the Fast timer should be used. This timer counts
time in units of 100ms or 1/10 of seconds.
For longer time periods, the Slow timer should be used. This timer is derived from the Fast timer and
therefore counts time in multiples of the Fast timer. The default setting of the Slow timer is to count
time in seconds. It is possible to alter the timing mechanism of the Slow timer to count in larger units of
time via the programming port.
5.8.2
Explanation of Timer Operation in a Timer Sequence
With reference to any one of the special timer sequences:
When the alarm point moves from a state where the timer is stopped to a state where the timer is
running, the timer will be started.
When the alarm point moves from a state where the timer is running to a state where the timer is also
running, the timer is allowed to continue timing.
When an alarm point moves from a state where the timer is running to a state where the timer is
stopped, the timer is put into the timed-out (stopped) state.
5.9
Selecting Serial Port Settings
The Omni8/16C can be equipped with an optional RS232/485 serial port. This port supports the Modbus
protocol. In Switch-Set or Soft-Set mode, inputs and outputs can be read via the serial port using standard
Modbus commands. Please refer to Section 10 for the layout of Modbus Registers that are available in the
Omni8/16C.
5.9.1
Default Settings
When the unit is in Switch set mode (refer to settings A or B of section 5.4), the unit may be accessed
via Modbus without changing the dipswitch settings at all. In this mode, communications settings are
fixed as follows:
Table 5-4 – Default Serial Port Settings with SW1-8 OFF
Default Modbus Settings with SW1-8 OFF
Modbus Slave Address
2
Comms settings
ASCII; 9600 baud; No Parity, 7 Data bits, 2 Stop Bits
5.9.2
Modbus Address and Mode Settings
In applications where the Modbus Slave address and/or comms settings are to be different from the
default settings as shown in the table above then set SW1-8 ON to enable SW2 for additional serial port
settings.
