OPTO 22 B3000-B, Руководство пользователя

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ADDRESSING I/O
B3000-B Serial Brains User’s Guide 8
ADDRESSING I/O
B3000-B and B3000-B-OMUX brains are connected to a SNAP B-series I/O rack, which can hold either 8, 12, or
16 SNAP modules. Digital modules (either input or output) contain four channels of I/O. Analog input modules
contain two channels and analog output modules contain one or two channels. Both analog and digital
modules can be on the same rack.
NOTE: Some SNAP modules cannot be used with these brains. For example, analog modules with four or more points
cannot be used; high-density digital modules cannot be used. Also, some newer modules require different processing
and cannot be used with these brains. Consult the module’s data sheet for compatibility information.
A B3000-B or B3000-B-OMUX is capable of addressing a maximum of 32 channels of digital I/O and 32
channels of analog I/O. However, the I/O mounting racks will not accommodate 32 channels of both digital
and analog. The actual number of channels available depends on the combination of modules you choose.
For example, the SNAP-B16M rack can mount 16 modules. Up to eight of these modules can be digital,
providing 32 channels of digital I/O. The remaining eight module positions can be analog, providing up to 16
channels of analog I/O. However, if all 16 modules are analog (no digital modules at all), up to 32 channels of
analog I/O are available.
I/O on these brains is divided into four addresses (two digital I/O and two analog I/O). The digital addresses are
base+0 and base+1. The analog addresses are base+2 and base+3. Therefore, if the brain is configured at
address 12, the digital addresses would be 12 and 13 and the analog would be 14 and 15. See the following
page for an illustration of the rack with digital and analog modules, showing their addresses.
First Four Module Positions (0-3)— As you see in the illustration on the following page, each of the first four
module positions on the rack can hold either a digital or an analog module. These first four positions can be all
analog, all digital, or any mix of both.
These four positions constitute the 16 digital channels of digital address base+0, and the first eight analog
channels of analog address base+2.
Second Four Module Positions (4-7) —Like the first four module positions, each position in the second
group of four can hold either a digital or an analog module. They can be all analog, all digital or any mix of
both.
These four positions constitute the 16 digital channels of digital address base+1, or the second eight analog
channels of analog address base+2.
Last Eight Module Positions (8-15)— These positions hold analog modules only. These eight positions
constitute the 16 analog channels of analog address base+3.