A polling device cyclically retrieving information from different answering stations controls the different answering stations with differing regularity, for which purpose addresses of the answering stations are stored in a polling memory with differing regularity. If a polling device has received no information when polling an answering station, it is bypassed on one of the next occasions. A note bit is stored for this purpose in the polling control memory under the address which has just been polled. If the same position in the polling memory is again reached after a polling cycle, the note bit causes the address not to be read and the answering station to be bypassed once instead; the note bit is again deleted. IMAGE
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