User guide

Data Communications with the Watlow Series 988 Family
Temperature/process Controller Prompt Table
986, 987,
988, 989
Name Description Read (?) and/or Write (=) Syntax Range
data.1 data.2
Modbus
address
6.2
Command Summary Series 986-989, Chapter 6
Table 6.2 -
A2HI to ALM
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CAUTION:
Avoid writing <=>
continuously, such
as ramping set
points or repetitive
loops, to the
Series 986-989
EEPROM memory.
Continuous writes
may result in
premature control
failure, system
downtime and
damage to
processes and
equipment.
NOTE:
The number of
decimal places
returned by many
of these
commands is
determined by the
DEC1, DEC2, IN1
or IN2 setting.
(This does not
apply to Modbus
Protocol.)
A2HI Output 2 Alarm High ? <sp> A2HI <cr> Process: A2LO to sensor high range
14 = <sp> A2HI <sp> data.2 <cr> Deviation: 0 to 9999°
Rate: 0 to 9999°/minute
Default: RH, 999°, or 999°/min.
A2LO Output 2 Alarm Low ? <sp> A2LO <cr> Process: sensor low range to A2HI
13 = <sp> A2LO <sp> data.2 <cr> Deviation: -999 to 0°
Rate: -9999 to 0°/minute
Default: RL, -999°, or -999°/min.
A3HI Output 3 Alarm High ? <sp> A3HI<cr> Process: A3LO to sensor high range
16 = <sp> A3HI <sp> data.2 <cr> Deviation: 0 to 9999°
Rate: 0 to 9999°/minute
Default: RH, 999°, or 999°/min.
A3LO Output 3 Alarm Low ? <sp> A3LO <cr> Process: sensor low range to A3HI
15 = <sp> A3LO <sp> data.2 <cr> Deviation: -999 to 0°
Rate: -999 to 0°/minute
Default: RL, -999°, or -999°/min.
ACAL Analog Offset ? <sp> ACAL <cr> -999 to 999°F
94 = <sp> ACAL <sp> data.2 <cr> -555 to 555°C
-999 to 999 units
Default: 0°F, 0°C, 0 units
AL2 Alarm 2 Type ? <sp> AL2 <cr> 0 = Deviation Alarm, Input 2
74 = <sp> AL2 <sp> data.2 <cr> 1 = Process Alarm, Input 2
2 = Process Alarm, Input 1
3 = Deviation Alarm, Input 1
4 = Rate Alarm, Input 1
Default: 2
AL3 Alarm 3 Type ? <sp> AL3 <cr> 0 = Deviation Alarm, Input 2
79 = <sp> AL3 <sp> data.2 <cr> 1 = Process Alarm, Input 2
2 = Process Alarm, Input 1
3 = Deviation Alarm, Input 1
4 = Rate Alarm, Input 1
Default: 2
ALGO Algorithm ? <sp> ALGO <cr> 0 = two sets of PID prompts [Pid2]
100 = <sp> ALGO <sp> data.2 <cr> 1 = one set of PID prompts [Pid]
2 = prop/derivative w/manual reset [Pdr]
3 = 1 process output both heat or cool [dUPL]
Default: 1
ALM Alarm Status ? <sp> ALM <cr> 0 = No alarms occurring (0000 0000)
3 (Writing a 0 clears = <sp> ALM <sp> 0 <cr> Bit 1 = A2LO (0000 0001)
next alarm.) Bit 2 = A2HI (0000 0010)
Bit 3 = A3LO (0000 0100)
Bit 4 = A3HI (0000 1000)