Rockwell Automation 1771-N SERIES High Resolution Analog Module User Manual - Manual (Page 108)

Block Transfer Write and Block Transfer Read Configurations for 2 Output/2 Input 1771-N Series Modules D–4
Publication 1771ĆUM127B-EN-P - December 2002
Definition
Decimal Bit
(Octal Bit)
Word
Word 18
Bits 00-15
(00-17)
High scale value for channel 3.
Word 19
Bits 00-15
(00-17)
Low alarm value for channel 3.
Word 20
Bits 00-15
(00-17)
High alarm value for channel 3.
Word 21
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.
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 22 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 lagfilter 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 23 Bit 11 (13) Constant = 0
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 24 thru 30 Same as words 17 thru 23 but for channel 4.
Words 31 thru 58 Null