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Ntpollnetwork polling rate, Ntpoll network, Polling rate – Parker Hannifin GEM6K User Manual

Page 30: Ntpoll

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3. Map a range of integer elements in the AB PLC to a range of integer (

VARI

) variables in the 6K (

NTMPWI

command).

4. Start polling the AB device at a specific polling interval (

NTPOLL

command). This updates integer data elements

in the AB PLC with the data from the mapped

VARI

variables in the 6K.

NOTE: The

VARI

variables in the 6K are 32 bit values, but the integers in the AB PLC are 16 bit values.

Therefore, the range for the

VARI

variables must be kept in the range –32767 to +32767.

Saved in Non-Volatile Memory

This command is saved in the controller’s non-volatile memory, and is remembered on power-up
and RESET.

Potential Error Conditions:

• You are not allowed to map the same 6K

VARI

variables for read and write functions. Nor are you allowed to map

the same 6K

VARI

variables to another PLC. If you attempt either of these conditions, the 6K will not accept the

NTMPWI

command and will transmit the error message “

VARIABLE MAPPING CONFLICT…

”.

• If you attempt to write to an AB data file of the wrong type, or to a non-existent data element, the 6K will not

accept the

NTMPWI

command, it will transmit the error message “

ERROR, INVALID FILE TYPE, NUMBER OR

SIZE…

” and it will automatically stop polling all mapped binary and integer variables (equivalent to executing the

NTMPRBi,i,0,i

,

NTMPWBi,i,0,i

,

NTMPRIi,i,0,i

, and

NTMPWIi,i,0,i

, commands).

Control over Polling: If you want to stop the 6K from writing integer data to the PLC, but continue to exchange

NTMPRI

,

NTMPRB

and

NTMPWB

data, use the

NTMPWIi,i,0,i

command. If you need to stop polling all mapped variables, use the

nNTPOLL0

command.

Example:
2NTIP1,172,54,125,34

; Identify network server #2 as an Allen-Bradley PLC at
; IP address 172.54.125.34

2NTCONN1

; Attempt connection to network server #2

2NTMPWI9,0,15,20

; File 9, elements 0-14, in the AB PLC are mapped to
; the 6K's integer variables VARI20-VARI34

2NTPOLL50

; Start polling network server #2, set interval to 50 ms

VARI = 42

; The value of AB file 9, element 5, will be set to 42,
; because it is mapped to VARI25

NTPOLL

Network Polling Rate

Type:

Network

Product Rev

Syntax:

NTPOLL

Units:

n = network server #
i = polling rate (milliseconds)

Range:

n = 1-6

i = 0 (disable polling) or 1-9999 (50 is recommended)

Default:

0 (disabled)

Response:

1NTPOLL: *1NTPOLL50

See Also:

NTIP, NTCONN, NTMPRB, NTMPRI, NTMPWB, NTMPWI

6K 5.3

The

NTPOLL

command establishes the rate at which the 6K polls the Ethernet server devices for information:

• Allen-Bradley

PLC

Devices:

NTPOLL

sets the rate at which the 6K reads and writes the

VARI

and

VARB

variables

that are mapped to the Allen-Bradley PLC. Variables are mapped with the

NTMPRB

,

NTMPRI

,

NTMPWB

and

NTMPWI

commands.

• OPTO22:

NTPOLL

sets the rate for polling or changing the states of the input and output modules on the OPTO22.

OPTO22 outputs are controlled with the

\OUT

and

\ANO

commands, and the inputs are monitored with the

\IN

,

\ANI

,

\TANI

,

\TANO

,

\TIN

,

\TIO

,

\TOUT

commands.

The polling rate affects the 6K overall command execution speed (slowing the polling rate will speed up the 6K’s
command processing).

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