Word 8: Command Control, Operational Commands The command control word is used to control the unit. Each bit gives access to a command or state as if the operator was using the keypad. Application Layer Bits initiating a command (7 to 12) must change state in order to cause the command to begin. For example, to reset totalizer 1, Bit 9 must be set to 0, then changed to 1. It can stay set or clear for any period. Bit 00 and 03: PID Mode Sets the mode of PID control to either manual (output determined by P410 – PID Manual) or auto (output determined by PID control in instrument). Bit 02 and 05 Setpoint Source Controls the location of the setpoint.
If it is set as “local”, then the setpoint used is internal to the BW500. If the setpoint source is set to “remote”, then the setpoint is controlled by a mA input. For setpoint control through communications this must be set to “local.” Bit 01 and 04: Freeze Suspends PID function when PID Mode = 1 (“auto”) and holds the output at the last value. PID functionality resumes when the freeze bit is cleared. Bit 06: Zero Sets the zero point for calibration of the belt scale. This is a momentary setting that must be reset to “0” once the input is accepted. To check that the input was accepted read word 0, bit 7 (zero status) and ensure it shows a “1”. Once it shows a “1” then reset this bit to “0”.
7ML19981BH02 SmartLinx DeviceNet – INSTRUCTION MANUAL Page 35 Bit # Description Bit Clear (0) Bit Set (1) 00 PID 1 mode manual auto 01 PID 1 freeze no yes 02 PID 1 setpoint source local remote 03 PID 2 mode manual auto 04 PID 2 freeze no yes 05 PID 2 setpoint source local remote 06 zero no change start 07 span no change start 08 reset totalizer 1 no change reset 09 reset totalizer 2 no change reset 10 reset batch totalizer no change reset 11 print print 12 reserved 13 reserved 14 reserved 15 reserved