RF Inventory

Warehouse inventory control using lift truck mounted radio frequency terminals. (PLCs).

All motion is manually directed in this warehouse. The computer is used to track the content of the storage bins, select an appropriate empty bin for incoming inventory, and direct the lift driver to a bin when orders are being filled.

Each storage bin and pallet is bar coded. The lift trucks are equiped with RF terminals and bar code scanners. The operator picks from a list of actions and is notified when orders for material have been received.

Even though the computer selects empty bins for incoming material, and allocates material from specific bins when orders are received, the lift operator may override the computer's selection simply by scanning a different bin and verify that it is an override and not a mis-scan.

The area server is a pair of DEC dual Pentium computers with a common, external RAID tower. An external HP 4mm DAT drive can be connected to either server. A Comtrol Rocket Port serial adapter is installed for multiple serial communications channels to the OpenVMS host.

There are two Intermec bar code label printers that are used for replacement labels on bins and product. These printers are equiped with parallel ports with external ethernet print servers.

An LXE RF Terminal controller is connected to the server and two LXE RF base stations via TCP/IP. Each truck is equiped with an LXE RF terminal and Symbol bar code scanner.

Each server is running NT Server 4.0, ORACLE 7.3, and SL-Net 2.2 (Seattle Lab's telnet package for NT). The application is written in Delphi 2.0 for both the windows maintenance and monitoring screens and VT-240 emulated console screens for the RF terminals. Reports are written with the Report Smith feature of Delphi. A Delphi program also runs as an NT Service to communicate with order processing and inventory inquiries from an OpenVMS host.

The warehouse contains packaging material and is attached to the manufacturing facility. There are no temperature extremes or corrosive vapors; however, there is a great deal of dust and debris in the air.

The actively used nodes are on a semi-isolated LAN segment, but can address any of the other stations on the network. Neither of the servers are domain controllers. The domain controller and its backup are part of the existing equipment as are a number of Win95 workstations that connect to these servers for data entry, on-line inquiry and report processing.

Except for the Scheduling and Order Entry application on the corporate host this application is self-contained. The only external access to the database is via Win95 workstations with this software installed. The Order Entry application communicates via dedicated serial interfaces (one for input and another for responses) using structured messages.

Some of the artwork used at this site is from Celtic Web Art. Check it out!