6F8C0845 694.2 S Controller Interface Buffer Memory Configuration4The S controller ladder program checks this register for "1" to be set after a request isissued to the DN611. When the "1" is set in the register, the ladder program readsDN611 response data from the acknowledgement area, then writes "0" in the register.0: No response.1: DN611 has responded to the S controller.Other than 0 and 1: Reserved(4) Request area (0334H to 03FBH: 200 words): S controller →→→→ DN611This area is to write request data in when the S controller issues a request to theDN611.Request data is written in the area beginning with 0728H.There are six types of requests that the S controller issues to the DN611 as follows:(a) Reset request(b) Parameter setting request (local node)(c) Parameter setting request (slave device)(d) DN611 operation mode control request(e) RAS information read request(f) Time setting requestThe above six requests vary in data composition as described in 4.3 Requests to theDN611.(5) Acknowledgement area (02D0H to 0333H: 100 words): DN611 → S controllerWhen the S controller issues a request to the DN611, the DN611 sets response datato the S controller in this acknowledgment area. Response data is setbeginning with 02D0H. The request data composition is described in 4.3 Requests tothe DN611.(6) How to use the semaphore areaFigure 4-15 shows how to use the areas and registers discussed in Items (1) to (5).The shaded parts of the figure indicate that "1" has been set in each flag register and"256" in the request register.(a) Use an MREAD instruction to read the acknowledgement flag register and tocheck that it reads 0. If it reads other than 0, write "0" in in it (for the first timeonly).(b) Use an MWRITE instruction to write request data to the DN611 in the requestarea (beginning with 0334H).(c) Use an MWRITE instruction to write "1" in the request flag register.(d) Use an MWRITE instruction to write "1" in the request register.(e) Use an MREAD instruction to read the acknowledgement flag register and waitsuntil it reads 1.(f) Use an MREAD instruction to read response data of the DN611 from theacknowledgement area when the acknowledgement flag register reads 1.(02D0H at the top).(g) Use an MWRITE instruction to write "0" in the acknowledgement flag register.(Returns to b).