Product Name:  Siemens S7-1500 PLC Digital-Input-Module SM522

Brand Name: Siemens 

Model:6ES7521-1BL00-0AB0

SIMATIC S7-1500, digital input module DI 16xDC 24V HF, 16 channels in groups of 16; input delay 0.05..20 ms; Input type 3 (IEC 61131); Diagnostics, hardware interrupts: Front connector (screw terminals or push-in) to be ordered separately

DI 16x24VDC HF;
digital input module with 16 channels for recording 24 V AC signals; one potential group; input delay 0.05 … 20 ms; input type 3 (IEC 61131); parameterizable diagnostic and process alarms; option of using two channels for simple counter functions up to 1 kHz

DI 16x24VDC HF;
digital input module with 32 channels for recording 24 V AC signals; two potential groups; input delay 0.05 … 20 ms; input type 3 (IEC 61131); parameterizable diagnostic and process alarms; option of using two channels for simple counter functions up to 1 kHz

DI 16x24VDC SRC BA;
digital input module with 16 channels for recording 24 V DC signals; active low; one potential group; fixed input delay 3.2 ms; input type 3 (IEC 61131)

DI 16x230VAC BA;
digital input module with 16 channels for recording 230 V AC signals; four potential groups; input delay 20 ms; input type 1 (IEC 61131)

DI 16×24…125VUC HF;
digital input module with 16 channels for recording 24 … 125 V UC signals; 16 potential groups; input delay 0.05 … 20 ms (DC) or 20 ms specified for (AC); parameterizable diagnostic and process alarms

The following digital input modules with a width of 25 mm are available:

DI 16x24VDC BA;
digital input module with 16 channels for recording 24 V DC signals; sinking input; one potential group; fixed input delay 3.2 ms; input type 3 (IEC 61131)

DI 32x24VDC BA;
digital input module with 32 channels for recording 24 V DC signals; sinking input; one potential group; fixed input delay 3.2 ms; input type 3 (IEC 61131)