Activation Direction - HELIX GRANVILLE-PHILLIPS Convectron ATM Instruction Manual

Chapter 4
Table 4-9 Relay default activation, range, and hysteresis
Relays Assignment
Setpoints Vacuum chamber
1 and 3 pressure
Setpoints Differential pressure
2 and 4
50
Example PC command from host: #01PC1A+1.01E–01 ↵
Response from module:
Example PC command from host: #01PC1D+2.00E–01 ↵
Response from module:
The "PC1" value identifies process control relay 1.
The "A" (activation) and "D" (deactivation) pressure values determine
activation and deactivation pressures at which the relay switches
states.
• If the "D" value is greater than the "A" value, the relay will always
activate with decreasing pressure and deactivate with increasing
pressure. See Figure 4-6 on page 51.
• If the "A" value is greater than the "D" value, the relay will always
activate with increasing pressure and deactivate with decreasing
pressure. See Figure 4-7 on page 51.
• If you enter equal "A" and "D" values, the module software will
increase the "D" value by the minimum software defined hysteresis.
In default mode, relays 1 and 3 are assigned to the Convectron gauge
and are set to activate with decreasing vacuum chamber pressure and
deactivate at a higher pressure than the activation pressure, as
illustrated in Figure 4-6.
In default mode, relays 2 and 4 are assigned to the differential pressure
sensor and are set to activate with increasing differential pressure and
deactivate at a lower pressure than the activation pressure, as
illustrated in Figure 4-7.

Activation direction

Decreasing pressure
Increasing pressure
Convectron
*01 PROGM OK ↵
*01 PROGM OK ↵
Range
• Operating range:
–4
1.0 x 10 to 9.99 x 10
Torr
• Default setting is out of
range, relay inoperable
• Operating range:
–750 to +125 Torr
• Default setting is out of
range, relay inoperable
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ATM Vacuum Gauge Module Instruction Manual
Hysteresis
Dependent on activation
2
and deactivation pressures
Dependent on activation
and deactivation pressures