Write programs for an Allen Bradley CompactLogix PLC and an Automation Direct OIU. Context below. Specifics will be provided following the selection of a skilled programmer and sign off on appropriate documentation - e.g. - contract, non disclosure agreement, etc.
Each product may be operated either manually or automatically. Operating mode is chosen for each product independently using a four position selector switch (A-B-C-D) provided for each product (ten total) on the door of the control panel mounted on the HPU.
A product operating in the A mode will be automatically modulated to control input elevation to the desired (preprogrammed) setpoint. So that all the products operating in this mode are as close as possible to the same elevation, if the control must lower a product to maintain input elevation, the product with the highest product elevation will be lowered. Similarly, if the control must raise a product to maintain input elevation, the product with the lowest product elevation will be raised.
A product operating in the B mode will be automatically modulated to keep the product elevation a fixed distance below the input elevation. All products operating in the B mode will be maintained at the same elevation.
Each product operating in the C mode will be automatically modulated to keep the product elevation at a fixed preset elevation. This preset elevation can be entered independently by operating personnel for each product through the OIU/HMI.
Each product operating in the D-manual mode can be positioned at the fully lowered (open), fully raised (closed), or any intermediate position independently from other products through the use of dedicated CLOSE and OPEN pushbuttons provided for each product in the door of the remote control station or the control panel mounted on the HPU. The active control location is determined independently for each product by the position of the LOCAL-REMOTE selector switches, one for each product, ten total, in the door of the control panel on the HPU. Actuating the CLOSE or OPEN pushbutton will cause motion in the selected direction until the pushbutton is released or the end of product travel is reached.
Whenever product movement is required, one of the two hydraulic pump motors is started. The two pumps alternate duty each time a pump start is required. Should one of the pumps fail to produce flow as measured by a flow switch, a GENERAL ALARM will be indicated and the other pump will be automatically started. The pumps do not run simultaneously.