1756-CFM/ABPLC模塊
命令報(bào)文中10F6H為D123的地址,04H表示要讀入4個(gè)字節(jié)的數(shù)據(jù)。校驗(yàn)和SUM=30H+31H+30H+46H+36H+30H+34H+03 H=174H,溢出部分不計(jì),故SUMH=7,SUAIL=4,相應(yīng)的ASCⅡ碼為“37H”,“34H”。應(yīng)答報(bào)文中4個(gè)字節(jié)的十六進(jìn)制數(shù),其相應(yīng)的ASCⅡ碼為8個(gè)字節(jié),故應(yīng)答報(bào)文長度為12個(gè)字節(jié)。
根據(jù)PC與FX系列PLC的傳輸應(yīng)答過程,利用VB的MSComm控件可以編寫如下通信程序?qū)崿F(xiàn)PC與FX系列PLC之間的串行通信,以完成數(shù)據(jù)的讀取。MSComm控件可以采用輪詢或事件驅(qū)動(dòng)的方法從端口獲取數(shù)據(jù)。在這個(gè)例子中使用了輪詢方法
1756-CFM/ABPLC模塊
1756
MFR. PART NUMBER DESCRIPTION
1756-A10 10 SLOT CONTROLLOGIX CHASSIS
1756-A13 13 SLOT CONTROLLOGIC CHASSIS
1756-A17 CHASSIS 17 SLOT CONTROLLOGIX
1756-A4 4 SLOT CONTROLLOGIX CHASIS
1756-A7 7 SLOT CONTROLLOGIX CHASSIS
1756-BA1 LOGIX5000 BATTERY ASSEMBLY
1756-CFM 2 CHANNEL /2 OUT CONFIGURABLE FLOWMETER
1756-CNB CONTROLNET BRIDGE MODULE
1756-CNBR CONTROLNET REDUNDANT BRIDGE MODULE
1756-CP3 LOGIX5000 RS232 PROGRAMMER CABLE
1756-DHRIO 2 CHANNEL DH+ AND/OR RIO SCANNER
1756-DNB DEVICE NET BRIDGE/SCANNER MODULE
1756-DPALEN CONTROLLOGIC SYSTEM DOCUMENTATION SET PRINTED
1756-ENET ETHERNET/IP BRIDGE MODULE
1756-GTWY CONTROLLOGIC GATEWAY CONFIGURATION SOFTWARE
1756-GTWYR SUPT REINSTATEMENT CONTRACT FOR 1756GTWY
1756-GTWYS SUPT RENEWAL CONTRACT FOR 1756GTWY
1756-HSC 2 CHANNEL /4 OUTPUT HIGH SPEED COUNTER
1756-IA16 79-132 VAC INPUT 16PTS
1756-IA16I 79-132 VAC ISOLATED INPUT 16PTS
1756-IA8D VAC DIAGNOSTIC INPUT 8PTS
1756-IB16 VDC INPUT 16PTS
1756-IB16D VDC DIAGNOSTIC INPUT
1756-IB16I VDC ISLOTED INPUT 16PTS