Extended instructions
9.3 Distributed I/O (PROFINET, PROFIBUS, or AS-i)
S7-1200 Programmable controller
412 System Manual, V4.2, 09/2016, A5E02486680-AK
Set CODE1 and CODE2 to zero for the positive answer to the higher-level controller. If the
received data record is to be rejected, enter the negative answer to the higher-level
controller in Error Code 1 of the CODE1 and in Error Code 2 of the CODE2.
-device has received a request for a data record receipt, you must recognize the
delivery of this request within
a certain duration. After recognition, you must send an answer
-level controller within this time period. Otherwise, the I-device experiences a
timeout error which causes the operating system of the I
-device to send a negative answer
igher-level controller. For information on the value for the time period, refer to the
specifications of your CPU.
The STATUS output parameter receives the error information after the occurrence of an
error.
You can determine the operating mode of the RCVREC instruction with the input parameter
MODE. This step is explained in the following table:
0 Check whether a request for a data record receipt exists
If a data record from a higher-level controller exists on the I-device, the instruction only writes to the NEW,
SLOT, SUBSLOT, INDEX, and LEN output parameters. If you call the instruction several times with MODE =
0, then the output parameter only refers to one and the same request.
1 Receiving a data record for any subslot of the I-device
If a data record from a higher-level controller exists on the I-device for any subslot of the I-device, the instruc-
tion writes to the output parameter and transfers the data record to the parameter RECORD.
2 Receiving a data record for a specific subslot of the I-device
If a data record from a higher-level controller exists on the I-device for a specific subslot of the I-device, the
instruction writes to the output parameter and transfers the data record to the parameter RECORD.
3 Sending a positive answer to the higher-level controller
The instruction checks the request of the higher-level controller to receive a data record, accepts the existing
data record, and sends a positive acknowledgment to the higher-level controller.
4 Sending a negative answer to the higher-level controller
The instruction checks the request of the higher-level controller to receive a data record, rejects the existing
data record, and sends a negative acknowledgment to the higher-level controller. Enter the reason for the
rejection in the input parameters CODE1 and CODE2.
Note
After the receipt of a data record (NEW = 1), you must call the RCVREC instruction twice to
ensure complete processing. You must do this in the following order:
First call with MODE = 1 or MODE = 2
Second call with MODE = 3 or MODE = 4
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