Solartron Mobrey 3595 4C, User Manual

Page: 97 / 128

3595 4C User Manual Part Two IMP Commands
35952350 (CH01/AA)
1-45
1.3.7 ADDITIONAL COMMANDS FOR 3595 IMP TYPES 1H AND 1J
Definition of terms:
Physical Channel
These are the twenty channels present on the IMP connector block, in the range of one through twenty.
User Unit Conversion
A simple first-order conversion of the measurement unit (resulting from CHannel MOde) to required unit.
User Linearisation
A fifth-order linearisation from the measurement unit (resulting from CHannel MOde) to required unit.
Real-time Mode
An IMP outputs data in this ‘standard’ mode. The messages are streamed and real-time results appear
without a timestamp in Stream 0. For IMP types 1A, 1B, 1C, 1D, 1E, 2A and 2B, this is the only mode
available. The same mode can also be selected for IMP types 1H and 1J, but there are two additional
modes available:
time tag mode and historical mode. (See below)
Time Tag Mode
Same as real-time mode with an extended Stream 0 that includes a time tag.
Historical Mode
This mode is unique to IMP types 1H and 1J and does not use Streams 0 and 1. Stream 2 is enlarged to fill
the first 240 bytes of the receive page. All results, alarms, etc. from the IMP are passed through with a
timestamp. This mode must be used if buffering of IMP data during S-Net downtime is required. Stream 3
is preserved to return status and error information. (
Do not use the SA command while in continuous
historical mode, since this command uses Stream 0 and overlaps the same data space on the 3595 4C
Interface card
.)
Logic States
When channels 19 and 20 are used for ‘digital status’ inputs, the logic states recognised are:
•
logic 1 = switch open (off) = high impedance
•
logic 0 = switch closed (on) = low (zero) impedance
When the IMP is powered off, the switch is high impedance and is read as a ‘1’ by another IMP. The digital
channel output maintains this state until changed by a set-up command.