Parker PAC, Руководство по установке, Страница: 95 / 197

Module-Specific Messages
Apart from the Module error messages, the set of messages below contains details about the current
state of the PACIO AI4-mA 12 Bit Module. These messages are automatically reset when the state
concerned has returned to normal. They are combined into a single "Specific_Error" state of the Module
and output to the IO LED as "Module-specific error
Variable Data type Explanation
Channel_n_Overcurrent BOOL Input current > 20 mA

Specific_Error = TRUE
Channel_n_Open BOOL 4..20mA mode: input current < 4mA

Specific_Error = TRUE
Conversion Time
The analog signals are converted one-by-one down every channel. Disabling one or more channels will
shorten the entire analog-to-digital (A/D) conversion cycle.
Filter in this case means to compute an average when the set filter time is over.
Analog value conversion runs cyclically and is not synchronized with the receipt of EtherCAT telegrams.
The cycle consists of the analog value conversion plus transmitting the values into the EtherCAT data area.
The PACIO AI4-mA 12 Bit Module accepts the following times as the ideal EtherCAT cycle setup.
Number of Channels Cycle Time in ms
1 0.27
2 0.41
3 0.55
4 0.69
NOTE: If you are aiming for a high sampling frequency, the PAC should do the filtering (averaging)
because it will normally have much more processing power. Take the EtherCAT cycle into
account to assess how much the values stored by the EtherCAT master are up-to-date.
Quality of Analog Values
I/O Connections
page 85 for the 24VDC-
supply to the transmitter of every channel
For the passive current sensors, interconnect the " " and "0V" terminals.
Active current sensors:

Use the power supplied by the module if at all possible.

If power to the current sensors is supplied by an external source, connect the 0V terminal of that
power source to the 0V terminal of the module.