Measurement Computing TempScan/1100 - Manual (Page 65)

TempScan / MultiScan User's Manual 879596 System Configuration 4-7
Channel Configuration
The TempScan/1100 or MultiScan/1200 unit performs several sophisticated calculations on the raw voltage
before supplying it to the controlling computer. To perform such calculations, the unit must know the
channel transducer type, and configuring a channel is the process of describing the channel transducer to
the TempScan/1100 or MultiScan/1200 unit. Consequently, the configured channel becomes part of the
channel scan.
The TempScan/1100 system, including any connected Exp/10A and Exp/11A expansion units, accepts any
combination of three kinds of scanning cards. Meanwhile, the MultiScan/1200 system, including any
connected Exp/10A and Exp/11A expansion units, accepts any combination of two kinds of scanning
cards.
For the TempScan/1100 unit or the expanded TempScan/1100 system, the three scanning cards are:
• TempTC/32B: This thermocouple (T/C) scanning card contains 32 differential input channels.
• TempV/32B: This volts scanning card contains 32 differential input channels.
• TempRTD/16B: This RTD scanning card contains 16 differential input channels.
For the MultiScan/1200 unit or the expanded MultiScan/1200 system, the two scanning cards are:
• MTC/24: This thermocouple/volts scanning card contains 24 differential input channels.
• MHV/24: This high-voltage scanning card contains 24 differential input channels.
The modularity of the TempScan/1100 or MultiScan/1200 system eliminates the need for synchronizing
separate and possibly incompatible analog-to-digital (A/D) measuring instruments or boards. This is an
important consideration because many temperature measurement systems require a combination of
thermocouples, voltage, and RTD inputs.
The TempScan/1100 or MultiScan/1200 system is capable of sensing the scanning card type that is
plugged into a slot in the master unit or in one of its connected expansion units. When configuring a
channel, the configuration parameters must match the scanning card type. For example, with a
TempScan/1000 system, a volts type cannot be assigned to a channel on a thermocouple scanning card, and
a thermocouple type cannot be assigned to a channel on a volts scanning card. If you attempt to configure
a channel number that is of the wrong type or does not exist, a channel configuration error will be logged
in the Error Source Register.
Using the Configure Channels (
C ) command, the minimum channel configuration required is a channel
type assigned for a single channel number or a range of channel numbers. Those channels not included in
the channel scan do not have to be configured. In addition to channel type and channel number, each
channel included in the channel scan can have the optional values – high alarm setpoint, low alarm
setpoint, and hysteresis – associated with it. The TempScan/1100 or MultiScan/1200 alarms allow the unit
to produce an internal event when the value of a channel is outside of desired limits. These alarm events
can be used as a Trigger (trigger start event) or Stop (trigger stop event), or as a stimulus for TTL-level
signals. For more information on channel types, see command Configure Channels (
C ).
CAUTION
The channel configuration cannot be changed while the trigger is armed or an
acquisition is taking place.