JPS6039934A - Data collecting system in mca system - Google Patents

Abstract

PURPOSE:To attain data collection from slave stations as many as possible within a limited time by superimposing the transmission of a mobile station and that of a command station to perform continuously the relay at switching of communication direction in a control station. CONSTITUTION:A central station and a slave station continue to transmit a dummy signal STD of a system tone until the transmission of signals Ri+1 and Pi+1 rises in consecution with the end of transmission of required data signals Pi and Ri (i=1-n). Thus, the control station detects continuously the system tone and processes a polling signal and its response signal as if one signal were transmitted. As a result, the relay delay time at switching of signal transmission from the central station to the slave station or from the slave station to the central station is eliminated and data from a lot of slave stations is collected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of collecting data from a plurality of mobile stations (or slave stations) to a command station (or central station) using an MCA system.

Since the MCA system uses the Breathtalk communication method, the timing chart for data collection is as shown in FIG.

That is, polling P l- from the central station to each slave station 1 to n
In response to Pn, each slave station l to n sends response signals R1 to Rn.
return each.

The operation timing of the control station in this case is CPI~CPn
, CRI-CB, n. In other words, the relay timing of polling Pi-Pn is CPt-CPn,
The relay timing of response signals Rt-Rn from slave stations is C'
Rl -CTL n. During these relays, the control station requires a delay time t corresponding to the system tone detection time before starting the relay, as shown in the figure. When trying to collect data from as many slave stations as possible within a limited time, the number of polls is limited due to the delay time t, which poses one problem.

It is an object of the present invention to provide a method that can solve such problems and collect data from as many slave stations as possible within a limited time.

The present invention will be explained below with reference to the drawings.

FIG. 2 is a timing chart explaining the basic concept of the present invention. The central station or slave station sends a dummy signal STD containing only the system tone to the next data signal Ri+, l or Pi+1 after the transmission of the necessary data signal p i (!-t −n ) or 'li is completed. Continue sending until rises.

Because of this, the control station can detect system tones continuously, so the response signal and the polling signal can be detected continuously.
It can be treated as if it were just one signal transmission. Therefore, relay delay time when switching signal transmission from the central station to the slave station or from the slave station to the central station can be eliminated, making it possible to collect data from many slave stations. This effect is not very large in the case of communication such as voice that has a small number of mutual repetitions, but it becomes extremely It becomes something big.

Next, the effects of the present invention when using a signal speed of 1200 BF2 will be shown below. The conditions are set as follows.

l) Relay delay time 250 ms (300 bits)2)
Bit synchronization required bit 63 Bit 3) Frame synchronization required bit 15 Bit 4) Data 50 bits 5) Single line occupation time 20 seconds First, the timing chart of data collection using the conventional method under the above conditions is as shown in Figure 3. become.

As can be seen from FIG. 3, the unnecessary time for data collection for one station is 317×2=634 ms. Therefore, the number of slave stations that can be collected in one line occupation time (20 seconds) is 20.
．． 000/63. It becomes station i#31.

On the other hand, the timing chart of the method according to the present invention under the same conditions is as shown in FIG. From Figure 4, the time required to collect data for the first opening is (357+107) = 4
64 ms, after the second genus (107X2) = 2
It becomes 17 ms. Therefore, the number of slave stations that can be collected in 20 seconds is ((20,000-464)/217)+1
'==91 stations. According to the method of the present invention,
It is possible to collect approximately three times more data than conventional methods.

As described above, according to the present invention, data can be collected with maximum efficiency by eliminating delay time during relay.

[Brief explanation of drawings]

FIG. 1 is a timing chart of a conventional data collection system in an MCA system, FIG. 2 is a timing chart of data collection according to the present invention in an MCA system, and FIG.
1 and 4 are specific timing charts of FIG. 1 and FIG. 2, respectively. Agent Patent Attorney Uchihara IV-〉Usu.

Claims (1)

[Claims] In an MCA system, the data collection method in the MCA system is characterized in that transmissions between a mobile station and a command station are superimposed so that when the control station switches communication direction, this control station is continuously relayed. Data collection method.