Measurement Computing TempScan/1100 - Manual (Page 41)

TempScan / MultiScan User's Manual 889897 Expansion Unit 2-5
Slave Configuration
CAUTION CAUTION CAUTION CAUTION
Avoid linking two or more expansion chassis with the same slave address.
Otherwise, the unspecified addresses may result in operating errors.
For the master/slave configuration to operate correctly, the master unit must either be a TempScan/1100 or
MultiScan/1200; it cannot be an Exp/10A or Exp/11A expansion unit.
Furthermore, each Exp/10A unit must be assigned a unique slave address. Following simple binary
weighting, this slave address is set by using microswitches 5 through 8 of the rear panel DIP switch.
In the following figure, DIP microswitch 8 is in the up position, indicating the default slave address 1.
With all four microswitches 5, 6, 7 and 8 in the up position, this setting indicates a slave address of 15
(8 + 4 + 2 + 1). A maximum of 15 Exp/10A slave addresses can be set, while the address of 0 is not
allowed. The Exp/10A factory default is address 1.
Note: The address of 0 is not allowed because this is reserved for the master unit address.
Channel Assignment
Channels 1 through 32 are always in the TempScan/1100, and channels 1 through 24 are always in the
MultiScan/1200, while the channels in the Exp/10A expansion unit are treated as extended channels.
With the first Exp/10A slave unit, the first channel in the first scanning card is channel 33 in the
TempScan/1100 system, and channel 25 in the MultiScan/1200 system. With the same slave unit, the first
channel in the second scanning card is channel 65 in the TempScan/1100 system, and channel 49 in the
MultiScan/1200 system. The order of multiple Exp/10A expansion units are set up using the rear panel DIP
switches, as described earlier.
Even if a scanning card slot is left empty in the master unit and/or slave unit(s), the channel assignments
remain the same, as shown in the table. For a 16-channel TempScan/1100 scanning card, the system still
assigns 32 channels to the card slot with the second 16 channels ignored. Likewise, for a 12-channel
MultiScan/1200 scanning card, the system still assigns 24 channels to the card slot with the second 12
channels ignored. For example, if a 16-channel TempRTD/16B scanning module is installed in the first slot
of Logical Unit 2 (the first Exp/10A), then channels 33 through 48 will be assigned and channels 49 through
64 will be ignored.