BEHLMAN BL10000 Series, Руководство пользователя и техническое руководство

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5.8 THEORY OF OPERATION FOR GPIB \ RS232 INTERFACE
All BL series power supplies including the “I” option contain an additional circuit card providing a computer
interface. This interface may be one of two standards, IEEE 488 or RS232. This card controls the supply output
voltage, frequency , and range as well as providing data back to the controlling computer. Operation of the
interface card is described in the following section. See figure 5-2 below.
The heart of the interface card is the 80C196 micro processor U17. This device used in conjunction with a
programmable memory/logic device U18, provides all the required communication functions. RS232
communications are handled directly by U17 while IEEE 488 protocol is handled by buss controller U19. U19
is an industry standard TMS 9914. Data stored in the U18 EEPROM determines which communication proto
call is selected. EEPROM data also determines scale factor and other set up parameters which are determined
by the actual model and size of the unit being controlled.
Figure 5-2
Programmed output voltage and frequency data is applied to serial D/A convertors. These convertors provide
a 0 to 10Vdc output that is applied to the analog remote inputs of the host unit. Control of these parameters is
as described in the theory of operation for the power source.