Measurement Computing DBK Part 2 - Manual (Page 195)

Open Thermocouple Detection
DBK101 is equipped with open thermocouple detection. This means that a broken thermocouple wire [or
otherwise unconnected input] that is measured will result in an off-scale reading. This is accomplished by
applying a small bias current to each of the channel inputs. Whenever a valid input is absent, the bias
current saturates the input amplifier, resulting in the off-scale reading.
DBK101 Hub Configuration
Up to thirty-two DBK100/D or DBK100/T pods can be attached to a single DBK101 hub. Up to two
DBK101 hubs can be attached to a DaqBook/2000 Series device.* Each DBK101 must have a unique
address setting according to the base channels which occupy it..
CAUTION
Adjustment of the channel address must only be performed when the system
power is OFF. Failure to do so may result in equipment damage.
To assign a channel address to a DBK101; first locate the DIP switch on the unit’s rear panel. Three of
four micro-switches [on the DIP switch] are used to set the address. Position of the right-most switch is
irrelevant. After ensuring that the system power is OFF, adjust the micro-switches to set the desired
address. The following table explains various DIP switch settings.
Switch Number: 8 4 2 1
Starting Address Bank Select
Switch
8
Switch
4
Switch
2
Switch
1
Base Channels
occupied by DBK101
0 0 0 - Half (4 channels) N/A Channels (00-03)
0 0 1 - Full (8 channels) N/A Channels (00-07)
0 1 0 - Half (4 channels) N/A Channels (04-07)
0 1 1 - Full (8 channels) N/A Channels (04-11)
1 0 0 - Half (4 channels) N/A Channels (08-11)
1 0 1 - Full (8 channels) N/A Channels (08-15)
1 1 0 - Half (4 channels) N/A Channels (12-15)
1 1 1 - Full (0 channels) N/A No selected Channels.
DBK101 is inhibited.
Example A: Two DBK101 hubs, one with 8 channels and one with 4 channels.
1
st
DBK101 has 8 strings of DBK100 pods (1 string per DBK101 channel).
2 nd DBK101 has 4 strings of DBK100 pods (1 string each for DBK101channels: 0, 1, 2, and 3)
In this example the first DBK101 is using 8 channels and the user wants these assigned as channels (00 through
07) so he sets the DIP-switch to “0 0 1 0.” (See preceding table).
The second DBK101 is using 4 channels and the user wants these assigned as channels (08 through 11) so he sets
the DIP-switch to “1 0 0 0.” (See preceding table). If he set the switch to 0 0 0 0 in he would have an address
conflict since 00-03 is already accounted for by the first DBK101’s DIP-switch setting.
Example B: Two DBK101 hubs, both with 8 channels.
DBK Option Cards and Module 907994 DBK100 Series pg. 7