Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 21)

DESCRIPTION OF OPERATION 5-3
1557-UM050F-EN-P –June 2013
Speed Command
The function of the speed command block is to select one of 12 possible speed command inputs to serve
as the drive speed command. Bits 12-15 of the Logic Command are used to select the Speed Command
Input from the following list:
2 analog inputs (0-10V)
3 preset speed commands
6 SCANbus ports
1 preset jog speed command
The two analog speed command inputs accept 0-10V signals. The range of each of the analog inputs is
defined by two parameters. These parameters can be adjusted to cause the speed command to either
increase or decrease with an increasing analog input.
The six SCANport ports are multiplexed into a single SCANport input. The range of the digital input is
defined by two parameters in the same way as the analog inputs.
The selected speed command input is clamped to a minimum level set by parameter Speed Command
Minimum and a maximum level set by parameter Speed Command Maximum. (See Parameter and
Variable Description in Chapter 6.)