Nuremberg, Germany--Simplicity and size reduction need not mean less capability in logic controllers, and may even mean more. Take Siemens Industrial Automation Systems new LOGO! controller and switching series. These compact, 72 or 126 x 90 x 55-mm, devices can operate in a stand- alone mode or as slave stations under higher level controllers in an AS-i(TM) bus system. The basic version accommodates six inputs with four outputs (the longer variants double these), and allows 14 integrated functions ranging from simple "and"/"or" to clock-pulse generators, retentive ON delay, and counters. Longer and bus versions also feature an operating hours counter, impulse relay/pulse output, and trigger functions. Other LOGO! modules serve as dedicated power supplies or humfree switches.
In use, LOGO! is snapped onto a DIN rail, and inputs and outputs connected. A simple six-key operator pad on the unit is used to enter the desired control program. After entry, all logic operations, limit values, and integrated functions are displayed in block-diagram form on an LCD panel. Such simplicity aids in reprogramming for any future changes. In operation, the display depicts I/O switch states. An EEPROM retains programs and values in the event of power failure.
A front interface allows connecting either a PC cable or plug-in program modules that copy programs for use in other LOGO! applications. One such module retains counter contents and switch states if power fails, and another also prevents unauthorized displays, changes, or copying.
LOGO!Soft, an optional programming software package running under Windows 95, is available for convenient PC-based programming, test and simulation, revisions, archiving, and printing of control programs independent of the LOGO! controllers. In addition, Siemens has compiled a library of LOGO!Soft applications programs available on disk or from their website: www.aut.siemens.de/logo. A user simply the program desired, adapts it for their application, and transfers it to LOGO! via PC cable. Program updates are also available at the site.