Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual - Manual (Page 147)

Block Transfer Write and Block Transfer Read Configurations for 4 Output/4 Input 1771-N Series Modules H–5
Publication 1771ĆUM127B-EN-P - December 2002
Definition
Decimal Bit
(Octal Bit)
Word
Word 35
Bits 00-14
(00-16)
Rate alarm. If the channel's input changes at a rate faster than this value and the
alarm enable bit is set, the channel will indicate a rate alarm condition. Legal values
are from 0.05 to 50% of full scale per second.
Word 35
Bit 15 (17)
Alarm enable bit. If set to 1, the module will report high alarm, low alarm,
underrange, overrange, and rate alarm conditions. If 0, these warnings are
suppressed.
Word 36 Bits 00-07
Alarm deadband. This field creates a hysteresis effect on the low and high alarms.
For an alarm condition to be removed, the input signal must go above the low alarm
limit or below the high alarm limit by an amount equal to the specified deadband.
Alarm deadband values must be less than or equal to one half the difference of the
high and low alarm values.
Bits 08-15
(10-17)
Filter time constant. Specifies the time constant of a digital, first order lag filter on the
input in 0.1 second units. Legal values are 0.1 to 9.9 seconds. A value of 0 disables
the filter.
Bits 00-07
10 ohm offset. Compensates for a resistance offset on a 10 ohm copper RTD. Range
of +0.99 ohms, in units of 0.01 ohms. This field must be 0 for all other RTDs.
Bits 08-10
(10-12)
RTD type. Specifies type of RTD linearization on RTD channels:
001 = 100 ohm Pt, European standard;
010 = 100 ohm Pt. US standard;
011 = 10 ohm copper;
100 = 120 ohm nickel.
This field is 0 for non-RTD channels.
Word 37
Bit 11 (13) Constant = 0
Word 37
Bits 12-15
(14-17)
Thermocouple type. Specifies type of TC linearization on TC channels.
0000 = millivolts;
0001 = B;
0010 = E;
0011 = J;
0100 = K;
0101 = R;
0110 = S;
0111 = T.
This field must be 0 for non-thermocouple channels.
Words 38 thru 44 Same as words 31 thru 37 but for channel 6.
Words 45 thru 51 Same as words 31 thru 37 but for channel 7.
Words 52 thru 58 Same as words 31 thru 37 but for channel 8.