Omron 3G3MV-PDRT2 - Communications Data Setting Examples; Communications Data Reference Example

Chapter 6
6-17
Message Communications
Note 1. The Net Reference and Reference From Net functions cannot be changed during running.
Note 2. Under the DeviceNet protocol, the unit for the speed reference is always r/min. The number
of motor poles (2 to 39) must be set in parameter n035/o1-03 (frequency reference setting
and display units) when using DeviceNet (open network). After changing the unit setting,
turn the power OFF and then ON again.
Note 3. Cannot be changed during running.
Note 4. If a frequency reference value has been already set and the frequency display unit is
changed via the network, a frequency reference value higher than expected may result after
unit conversion. After changing the frequency display unit, always check the frequency ref-
erence value before starting an operation.
● Communications Data Setting Examples
Example 1: Finding the communications data for outputting a frequency of 60 Hz with the following
conditions set.
Number of poles set in n035/o1-03: 4
Speed scale (attribute 16): 0
• Converting frequency to rotational speed:
Frequency x 120 / number of poles = 60 x 120/4 = 1,800 r/min
• Converting rotational speed to minimum unit:
Rotational speed / unit = 1,800 / (1 r/min x 1/2
0
) = 1,800
• Converting communications data to hexadecimal: 1,800 (decimal) = 0708 (hex)
Example 2: Finding the communications data for outputting a frequency of 60 Hz with the following
condition set.
Frequency setting in n035/o1-03: 0 (Cannot be set with DeviceNet protocol.)
• Converting frequency to minimum setting unit:
Frequency / minimum unit = 60 / 0.01 = 6,000
• Converting communications data to hexadecimal: 6,000 (decimal) = 1,770 (hex)
Example 3: Finding the communications data for setting a one-minute acceleration time with the fol-
lowing condition set.
Time scale (attribute 1C): −3 (FD hex)
• Matching the acceleration time unit:1 minute = 60 seconds = 60,000 ms
• Converting acceleration time to minimum unit:
Acceleration time / unit = 60,000 / (1 ms x 1/2
−3
) = 7,500
• Converting communications data to hexadecimal: 7,500 (decimal) = 1D4C (hex)
● Communications Data Reference Example
In this example, the hexadecimal value 0BB8 that has been read is converted to frequency with the
following conditions set.
Number of poles set in n035/o1-03: 4
Speed scale (attribute 16): 1
• Converting communications data to decimal: 0BB8 (hex) = 3,000 (decimal)
• Converting from minimum unit to r/min:
Communications data x unit = 3,000 x (1 r/min x 1/2
1
) = 1,500 (r/min)