National Instruments NI-FBUS User Manual

Page 112

Advertising
background image

Appendix B

Troubleshooting and Common Questions

© National Instruments Corporation

B-3

NI-FBUS Configurator User Manual

The Fieldbus device stays in

OOS

mode even though the resource block

MODE_BCK.TARGET

=

Auto

and

MODE_BCK.ACTUAL

=

Auto

.

The Fieldbus device needs to be configured. Start by dragging the function
block in question, such as an AI, AO, or PID block, into the Function Block
Application Editor window. The block does not need to be connected with
anything else. Then, download the configuration—this will allow it to
execute on the device. If there are problems, try the following solutions:

Make sure that the resource block is in

Auto

mode—not

OOS

. This is

found by either checking which button is depressed in the resource
block’s block configuration window or by looking at the

MODE_BCK.ACTUAL

.

See if the

Options

parameter is in

Run

. If so, check the

Block_ERR

in the resource block—it should be zero.

Go to the I/O function block in question, and make sure that the

OUT/IN.status

is in

Good

… mode. If not, go to the

Block_ERR

parameter and see what the problem is.

The resource block must be in

Auto

mode for any other blocks in the device

to execute. The resource block is a good place to start troubleshooting if the
device is not behaving as desired. It has diagnostic parameters that help you
determine the cause of the problem.

A resource block specifies the general characteristics of the resource. This
includes the device type and revision, manufacturer ID, serial number, and
resource state. Each device has only one resource block. The resource block
also contains the state of all of the other blocks in the device.

If the device cannot change its

ACTUAL

mode to the

TARGET

mode, first

verify that you have downloaded the configuration to the device. If the
configuration has been downloaded, you can diagnose the problem by
looking at the

BLOCK_ERR

parameter of the function block. This parameter

often identifies the problem. For example, if the device resource block is
off-line, the

BLOCK_ERR

parameter will read

Resource Block Offline

,

indicating that you must change the resource block to

Auto

mode before

you can change the function block mode. Also, if the device is an FP-3000,
you can look at the additional parameters on the Diagnostics tab in the
block configuration window. Notice that the

LAST_BLOCK_EVENT

is not

cleared after an error condition clears. Check the time stamp to determine
whether the event you are looking at is current.

Advertising