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
ç
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.
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)